Button Class Reference

A base class for buttons. More...

#include <juce_Button.h>

Inheritance diagram for Button:

Classes
class	Listener
	Used to receive callbacks when a button is clicked. More...
struct	LookAndFeelMethods
	This abstract base class is implemented by LookAndFeel classes to provide button-drawing functionality. More...

Public Types
enum	ConnectedEdgeFlags { ConnectedOnLeft = 1 , ConnectedOnRight = 2 , ConnectedOnTop = 4 , ConnectedOnBottom = 8 }
	A combination of these flags are used by setConnectedEdges(). More...
enum	ButtonState { buttonNormal , buttonOver , buttonDown }
	Used by setState(). More...
Public Types inherited from Component
enum class	FocusContainerType { none , focusContainer , keyboardFocusContainer }
	A focus container type that can be passed to setFocusContainerType(). More...
enum	FocusChangeType { focusChangedByMouseClick , focusChangedByTabKey , focusChangedDirectly }
	Enumeration used by the focusGained() and focusLost() methods. More...
enum class	FocusChangeDirection { unknown , forward , backward }
	Enumeration used by the focusGainedWithDirection() method. More...

Public Member Functions
	~Button () override
	Destructor.
void	setButtonText (const String &newText)
	Changes the button's text.
const String &	getButtonText () const
	Returns the text displayed in the button.
bool	isDown () const noexcept
	Returns true if the button is currently being held down.
bool	isOver () const noexcept
	Returns true if the mouse is currently over the button.
void	setToggleable (bool shouldBeToggleable)
	Indicates that the button's on/off state is toggleable.
bool	isToggleable () const noexcept
	Returns true if the button's on/off state is toggleable.
void	setToggleState (bool shouldBeOn, NotificationType notification)
	A button has an on/off state associated with it, and this changes that.
bool	getToggleState () const noexcept
	Returns true if the button is 'on'.
Value &	getToggleStateValue () noexcept
	Returns the Value object that represents the button's toggle state.
void	setClickingTogglesState (bool shouldAutoToggleOnClick) noexcept
	This tells the button to automatically flip the toggle state when the button is clicked.
bool	getClickingTogglesState () const noexcept
	Returns true if this button is set to be an automatic toggle-button.
void	setRadioGroupId (int newGroupId, NotificationType notification=sendNotification)
	Enables the button to act as a member of a mutually-exclusive group of 'radio buttons'.
int	getRadioGroupId () const noexcept
	Returns the ID of the group to which this button belongs.
void	addListener (Listener *newListener)
	Registers a listener to receive events when this button's state changes.
void	removeListener (Listener *listener)
	Removes a previously-registered button listener.
virtual void	triggerClick ()
	Causes the button to act as if it's been clicked.
void	setCommandToTrigger (ApplicationCommandManager *commandManagerToUse, CommandID commandID, bool generateTooltip)
	Sets a command ID for this button to automatically invoke when it's clicked.
CommandID	getCommandID () const noexcept
	Returns the command ID that was set by setCommandToTrigger().
void	addShortcut (const KeyPress &)
	Assigns a shortcut key to trigger the button.
void	clearShortcuts ()
	Removes all key shortcuts that had been set for this button.
bool	isRegisteredForShortcut (const KeyPress &) const
	Returns true if the given keypress is a shortcut for this button.
void	setRepeatSpeed (int initialDelayInMillisecs, int repeatDelayInMillisecs, int minimumDelayInMillisecs=-1) noexcept
	Sets an auto-repeat speed for the button when it is held down.
void	setTriggeredOnMouseDown (bool isTriggeredOnMouseDown) noexcept
	Sets whether the button click should happen when the mouse is pressed or released.
bool	getTriggeredOnMouseDown () const noexcept
	Returns whether the button click happens when the mouse is pressed or released.
uint32	getMillisecondsSinceButtonDown () const noexcept
	Returns the number of milliseconds since the last time the button went into the 'down' state.
void	setTooltip (const String &newTooltip) override
	Sets the tooltip for this button.
void	setConnectedEdges (int connectedEdgeFlags)
	Hints about which edges of the button might be connected to adjoining buttons.
int	getConnectedEdgeFlags () const noexcept
	Returns the set of flags passed into setConnectedEdges().
bool	isConnectedOnLeft () const noexcept
	Indicates whether the button adjoins another one on its left edge.
bool	isConnectedOnRight () const noexcept
	Indicates whether the button adjoins another one on its right edge.
bool	isConnectedOnTop () const noexcept
	Indicates whether the button adjoins another one on its top edge.
bool	isConnectedOnBottom () const noexcept
	Indicates whether the button adjoins another one on its bottom edge.
void	setState (ButtonState newState)
	Can be used to force the button into a particular state.
ButtonState	getState () const noexcept
	Returns the button's current over/down/up state.
Public Member Functions inherited from Component
	Component () noexcept
	Creates a component.
	~Component () override
	Destructor.
	Component (const String &componentName) noexcept
	Creates a component, setting its name at the same time.
String	getName () const noexcept
	Returns the name of this component.
virtual void	setName (const String &newName)
	Sets the name of this component.
String	getComponentID () const noexcept
	Returns the ID string that was set by setComponentID().
void	setComponentID (const String &newID)
	Sets the component's ID string.
virtual void	setVisible (bool shouldBeVisible)
	Makes the component visible or invisible.
bool	isVisible () const noexcept
	Tests whether the component is visible or not.
bool	isShowing () const
	Tests whether this component and all its parents are visible.
virtual void	addToDesktop (int windowStyleFlags, void *nativeWindowToAttachTo=nullptr)
	Makes this component appear as a window on the desktop.
void	removeFromDesktop ()
	If the component is currently showing on the desktop, this will hide it.
bool	isOnDesktop () const noexcept
	Returns true if this component is currently showing on the desktop.
ComponentPeer *	getPeer () const
	Returns the heavyweight window that contains this component.
virtual void	userTriedToCloseWindow ()
	For components on the desktop, this is called if the system wants to close the window.
virtual void	minimisationStateChanged (bool isNowMinimised)
	Called for a desktop component which has just been minimised or un-minimised.
virtual float	getDesktopScaleFactor () const
	Returns the default scale factor to use for this component when it is placed on the desktop.
void	toFront (bool shouldAlsoGainKeyboardFocus)
	Brings the component to the front of its siblings.
void	toBack ()
	Changes this component's z-order to be at the back of all its siblings.
void	toBehind (Component *other)
	Changes this component's z-order so that it's just behind another component.
void	setAlwaysOnTop (bool shouldStayOnTop)
	Sets whether the component should always be kept at the front of its siblings.
bool	isAlwaysOnTop () const noexcept
	Returns true if this component is set to always stay in front of its siblings.
int	getX () const noexcept
	Returns the x coordinate of the component's left edge.
int	getY () const noexcept
	Returns the y coordinate of the top of this component.
int	getWidth () const noexcept
	Returns the component's width in pixels.
int	getHeight () const noexcept
	Returns the component's height in pixels.
int	getRight () const noexcept
	Returns the x coordinate of the component's right-hand edge.
Point< int >	getPosition () const noexcept
	Returns the component's top-left position as a Point.
int	getBottom () const noexcept
	Returns the y coordinate of the bottom edge of this component.
Rectangle< int >	getBounds () const noexcept
	Returns this component's bounding box.
Rectangle< int >	getLocalBounds () const noexcept
	Returns the component's bounds, relative to its own origin.
Rectangle< int >	getBoundsInParent () const noexcept
	Returns the area of this component's parent which this component covers.
int	getScreenX () const
	Returns this component's x coordinate relative the screen's top-left origin.
int	getScreenY () const
	Returns this component's y coordinate relative the screen's top-left origin.
Point< int >	getScreenPosition () const
	Returns the position of this component's top-left corner relative to the screen's top-left.
Rectangle< int >	getScreenBounds () const
	Returns the bounds of this component, relative to the screen's top-left.
Point< int >	getLocalPoint (const Component *sourceComponent, Point< int > pointRelativeToSourceComponent) const
	Converts a point to be relative to this component's coordinate space.
Point< float >	getLocalPoint (const Component *sourceComponent, Point< float > pointRelativeToSourceComponent) const
	Converts a point to be relative to this component's coordinate space.
Rectangle< int >	getLocalArea (const Component *sourceComponent, Rectangle< int > areaRelativeToSourceComponent) const
	Converts a rectangle to be relative to this component's coordinate space.
Rectangle< float >	getLocalArea (const Component *sourceComponent, Rectangle< float > areaRelativeToSourceComponent) const
	Converts a rectangle to be relative to this component's coordinate space.
Point< int >	localPointToGlobal (Point< int > localPoint) const
	Converts a point relative to this component's top-left into a screen coordinate.
Point< float >	localPointToGlobal (Point< float > localPoint) const
	Converts a point relative to this component's top-left into a screen coordinate.
Rectangle< int >	localAreaToGlobal (Rectangle< int > localArea) const
	Converts a rectangle from this component's coordinate space to a screen coordinate.
Rectangle< float >	localAreaToGlobal (Rectangle< float > localArea) const
	Converts a rectangle from this component's coordinate space to a screen coordinate.
void	setTopLeftPosition (int x, int y)
	Moves the component to a new position.
void	setTopLeftPosition (Point< int > newTopLeftPosition)
	Moves the component to a new position.
void	setTopRightPosition (int x, int y)
	Moves the component to a new position.
void	setSize (int newWidth, int newHeight)
	Changes the size of the component.
void	setBounds (int x, int y, int width, int height)
	Changes the component's position and size.
void	setBounds (Rectangle< int > newBounds)
	Changes the component's position and size.
void	setBoundsRelative (float proportionalX, float proportionalY, float proportionalWidth, float proportionalHeight)
	Changes the component's position and size in terms of fractions of its parent's size.
void	setBoundsRelative (Rectangle< float > proportionalArea)
	Changes the component's position and size in terms of fractions of its parent's size.
void	setBoundsInset (BorderSize< int > borders)
	Changes the component's position and size based on the amount of space to leave around it.
void	setBoundsToFit (Rectangle< int > targetArea, Justification justification, bool onlyReduceInSize)
	Positions the component within a given rectangle, keeping its proportions unchanged.
void	setCentrePosition (int x, int y)
	Changes the position of the component's centre.
void	setCentrePosition (Point< int > newCentrePosition)
	Changes the position of the component's centre.
void	setCentreRelative (float x, float y)
	Changes the position of the component's centre.
void	centreWithSize (int width, int height)
	Changes the component's size and centres it within its parent.
void	setTransform (const AffineTransform &transform)
	Sets a transform matrix to be applied to this component.
AffineTransform	getTransform () const
	Returns the transform that is currently being applied to this component.
bool	isTransformed () const noexcept
	Returns true if a non-identity transform is being applied to this component.
int	proportionOfWidth (float proportion) const noexcept
	Returns a proportion of the component's width.
int	proportionOfHeight (float proportion) const noexcept
	Returns a proportion of the component's height.
int	getParentWidth () const noexcept
	Returns the width of the component's parent.
int	getParentHeight () const noexcept
	Returns the height of the component's parent.
Rectangle< int >	getParentMonitorArea () const
	Returns the screen coordinates of the monitor that contains this component.
int	getNumChildComponents () const noexcept
	Returns the number of child components that this component contains.
Component *	getChildComponent (int index) const noexcept
	Returns one of this component's child components, by it index.
int	getIndexOfChildComponent (const Component *child) const noexcept
	Returns the index of this component in the list of child components.
const Array< Component * > &	getChildren () const noexcept
	Provides access to the underlying array of child components.
Component *	findChildWithID (StringRef componentID) const noexcept
	Looks for a child component with the specified ID.
void	addChildComponent (Component *child, int zOrder=-1)
	Adds a child component to this one.
void	addChildComponent (Component &child, int zOrder=-1)
	Adds a child component to this one.
void	addAndMakeVisible (Component *child, int zOrder=-1)
	Adds a child component to this one, and also makes the child visible if it isn't already.
void	addAndMakeVisible (Component &child, int zOrder=-1)
	Adds a child component to this one, and also makes the child visible if it isn't already.
void	addChildAndSetID (Component *child, const String &componentID)
	Adds a child component to this one, makes it visible, and sets its component ID.
void	removeChildComponent (Component *childToRemove)
	Removes one of this component's child-components.
Component *	removeChildComponent (int childIndexToRemove)
	Removes one of this component's child-components by index.
void	removeAllChildren ()
	Removes all this component's children.
void	deleteAllChildren ()
	Removes and deletes all of this component's children.
Component *	getParentComponent () const noexcept
	Returns the component which this component is inside.
template<class TargetClass >
TargetClass *	findParentComponentOfClass () const
	Searches the parent components for a component of a specified class.
Component *	getTopLevelComponent () const noexcept
	Returns the highest-level component which contains this one or its parents.
bool	isParentOf (const Component *possibleChild) const noexcept
	Checks whether a component is anywhere inside this component or its children.
virtual void	childrenChanged ()
	Subclasses can use this callback to be told when children are added or removed, or when their z-order changes.
virtual bool	hitTest (int x, int y)
	Tests whether a given point is inside the component.
void	setInterceptsMouseClicks (bool allowClicksOnThisComponent, bool allowClicksOnChildComponents) noexcept
	Changes the default return value for the hitTest() method.
void	getInterceptsMouseClicks (bool &allowsClicksOnThisComponent, bool &allowsClicksOnChildComponents) const noexcept
	Retrieves the current state of the mouse-click interception flags.
bool	contains (Point< int > localPoint)
	Returns true if a given point lies within this component or one of its children.
bool	contains (Point< float > localPoint)
	Returns true if a given point lies within this component or one of its children.
bool	reallyContains (Point< int > localPoint, bool returnTrueIfWithinAChild)
	Returns true if a given point lies in this component, taking any overlapping siblings into account.
bool	reallyContains (Point< float > localPoint, bool returnTrueIfWithinAChild)
	Returns true if a given point lies in this component, taking any overlapping siblings into account.
Component *	getComponentAt (int x, int y)
	Returns the component at a certain point within this one.
Component *	getComponentAt (Point< int > position)
	Returns the component at a certain point within this one.
Component *	getComponentAt (Point< float > position)
	Returns the component at a certain point within this one.
void	repaint ()
	Marks the whole component as needing to be redrawn.
void	repaint (int x, int y, int width, int height)
	Marks a subsection of this component as needing to be redrawn.
void	repaint (Rectangle< int > area)
	Marks a subsection of this component as needing to be redrawn.
void	setBufferedToImage (bool shouldBeBuffered)
	Makes the component use an internal buffer to optimise its redrawing.
Image	createComponentSnapshot (Rectangle< int > areaToGrab, bool clipImageToComponentBounds=true, float scaleFactor=1.0f)
	Generates a snapshot of part of this component.
void	paintEntireComponent (Graphics &context, bool ignoreAlphaLevel)
	Draws this component and all its subcomponents onto the specified graphics context.
void	setPaintingIsUnclipped (bool shouldPaintWithoutClipping) noexcept
	This allows you to indicate that this component doesn't require its graphics context to be clipped when it is being painted.
bool	isPaintingUnclipped () const noexcept
	Returns true if this component doesn't require its graphics context to be clipped when it is being painted.
void	setComponentEffect (ImageEffectFilter *newEffect)
	Adds an effect filter to alter the component's appearance.
ImageEffectFilter *	getComponentEffect () const noexcept
	Returns the current component effect.
LookAndFeel &	getLookAndFeel () const noexcept
	Finds the appropriate look-and-feel to use for this component.
void	setLookAndFeel (LookAndFeel *newLookAndFeel)
	Sets the look and feel to use for this component.
virtual void	lookAndFeelChanged ()
	Called to let the component react to a change in the look-and-feel setting.
void	sendLookAndFeelChange ()
	Calls the methods repaint(), lookAndFeelChanged(), and colourChanged() in this component and all its children recursively.
void	setOpaque (bool shouldBeOpaque)
	Indicates whether any parts of the component might be transparent.
bool	isOpaque () const noexcept
	Returns true if no parts of this component are transparent.
void	setBroughtToFrontOnMouseClick (bool shouldBeBroughtToFront) noexcept
	Indicates whether the component should be brought to the front when clicked.
bool	isBroughtToFrontOnMouseClick () const noexcept
	Indicates whether the component should be brought to the front when clicked-on.
void	setExplicitFocusOrder (int newFocusOrderIndex)
	Sets the focus order of this component.
int	getExplicitFocusOrder () const
	Returns the focus order of this component, if one has been specified.
void	setFocusContainerType (FocusContainerType containerType) noexcept
	Sets whether this component is a container for components that can have their focus traversed, and the type of focus traversal that it supports.
bool	isFocusContainer () const noexcept
	Returns true if this component has been marked as a focus container.
bool	isKeyboardFocusContainer () const noexcept
	Returns true if this component has been marked as a keyboard focus container.
Component *	findFocusContainer () const
	Returns the focus container for this component.
Component *	findKeyboardFocusContainer () const
	Returns the keyboard focus container for this component.
void	setWantsKeyboardFocus (bool wantsFocus) noexcept
	Sets a flag to indicate whether this component wants keyboard focus or not.
bool	getWantsKeyboardFocus () const noexcept
	Returns true if the component is interested in getting keyboard focus.
void	setMouseClickGrabsKeyboardFocus (bool shouldGrabFocus)
	Chooses whether a click on this component automatically grabs the focus.
bool	getMouseClickGrabsKeyboardFocus () const noexcept
	Returns the last value set with setMouseClickGrabsKeyboardFocus().
void	grabKeyboardFocus ()
	Tries to give keyboard focus to this component.
void	giveAwayKeyboardFocus ()
	If this component or any of its children currently have the keyboard focus, this will defocus it, send a focus change notification, and try to pass the focus to the next component.
bool	hasKeyboardFocus (bool trueIfChildIsFocused) const
	Returns true if this component currently has the keyboard focus.
void	moveKeyboardFocusToSibling (bool moveToNext)
	Tries to move the keyboard focus to one of this component's siblings.
virtual std::unique_ptr< ComponentTraverser >	createFocusTraverser ()
	Creates a ComponentTraverser object to determine the logic by which focus should be passed from this component.
virtual std::unique_ptr< ComponentTraverser >	createKeyboardFocusTraverser ()
	Creates a ComponentTraverser object to use to determine the logic by which keyboard focus should be passed from this component.
void	setHasFocusOutline (bool hasFocusOutline) noexcept
	Use this to indicate that the component should have an outline drawn around it when it has keyboard focus.
bool	hasFocusOutline () const noexcept
	Returns true if this component should have a focus outline.
bool	isEnabled () const noexcept
	Returns true if the component (and all its parents) are enabled.
void	setEnabled (bool shouldBeEnabled)
	Enables or disables this component.
float	getAlpha () const noexcept
	Returns the component's current transparency level.
void	setAlpha (float newAlpha)
	Changes the transparency of this component.
virtual void	alphaChanged ()
	Called when setAlpha() is used to change the alpha value of this component.
void	setMouseCursor (const MouseCursor &cursorType)
	Changes the mouse cursor shape to use when the mouse is over this component.
virtual MouseCursor	getMouseCursor ()
	Returns the mouse cursor shape to use when the mouse is over this component.
void	updateMouseCursor () const
	Forces the current mouse cursor to be updated.
virtual void	paintOverChildren (Graphics &g)
	Components can override this method to draw over the top of their children.
void	mouseMove (const MouseEvent &event) override
	Called when the mouse moves inside a component.
void	mouseEnter (const MouseEvent &event) override
	Called when the mouse first enters a component.
void	mouseExit (const MouseEvent &event) override
	Called when the mouse moves out of a component.
void	mouseDown (const MouseEvent &event) override
	Called when a mouse button is pressed.
void	mouseDrag (const MouseEvent &event) override
	Called when the mouse is moved while a button is held down.
void	mouseUp (const MouseEvent &event) override
	Called when a mouse button is released.
void	mouseDoubleClick (const MouseEvent &event) override
	Called when a mouse button has been double-clicked on a component.
void	mouseWheelMove (const MouseEvent &event, const MouseWheelDetails &wheel) override
	Called when the mouse-wheel is moved.
void	mouseMagnify (const MouseEvent &event, float scaleFactor) override
	Called when a pinch-to-zoom mouse-gesture is used.
void	setRepaintsOnMouseActivity (bool shouldRepaint) noexcept
	Causes automatic repaints when the mouse enters or exits this component.
void	addMouseListener (MouseListener *newListener, bool wantsEventsForAllNestedChildComponents)
	Registers a listener to be told when mouse events occur in this component.
void	removeMouseListener (MouseListener *listenerToRemove)
	Deregisters a mouse listener.
void	addKeyListener (KeyListener *newListener)
	Adds a listener that wants to hear about keypresses that this component receives.
void	removeKeyListener (KeyListener *listenerToRemove)
	Removes a previously-registered key listener.
virtual void	modifierKeysChanged (const ModifierKeys &modifiers)
	Called when a modifier key is pressed or released.
virtual void	focusGainedWithDirection (FocusChangeType cause, FocusChangeDirection direction)
	Called to indicate that this component has just acquired the keyboard focus.
virtual void	focusOfChildComponentChanged (FocusChangeType cause)
	Called to indicate a change in whether or not this component is the parent of the currently-focused component.
bool	isMouseOver (bool includeChildren=false) const
	Returns true if the mouse is currently over this component.
bool	isMouseButtonDown (bool includeChildren=false) const
	Returns true if the mouse button is currently held down in this component.
bool	isMouseOverOrDragging (bool includeChildren=false) const
	True if the mouse is over this component, or if it's being dragged in this component.
Point< int >	getMouseXYRelative () const
	Returns the mouse's current position, relative to this component.
virtual void	resized ()
	Called when this component's size has been changed.
virtual void	moved ()
	Called when this component's position has been changed.
virtual void	childBoundsChanged (Component *child)
	Called when one of this component's children is moved or resized.
virtual void	parentSizeChanged ()
	Called when this component's immediate parent has been resized.
virtual void	broughtToFront ()
	Called when this component has been moved to the front of its siblings.
void	addComponentListener (ComponentListener *newListener)
	Adds a listener to be told about changes to the component hierarchy or position.
void	removeComponentListener (ComponentListener *listenerToRemove)
	Removes a component listener.
void	postCommandMessage (int commandId)
	Dispatches a numbered message to this component.
int	runModalLoop ()
	Runs a component modally, waiting until the loop terminates.
void	enterModalState (bool takeKeyboardFocus=true, ModalComponentManager::Callback *callback=nullptr, bool deleteWhenDismissed=false)
	Puts the component into a modal state.
void	exitModalState (int returnValue=0)
	Ends a component's modal state.
bool	isCurrentlyModal (bool onlyConsiderForemostModalComponent=true) const noexcept
	Returns true if this component is the modal one.
bool	isCurrentlyBlockedByAnotherModalComponent () const
	Checks whether there's a modal component somewhere that's stopping this one from receiving messages.
virtual bool	canModalEventBeSentToComponent (const Component *targetComponent)
	When a component is modal, this callback allows it to choose which other components can still receive events.
virtual void	inputAttemptWhenModal ()
	Called when the user tries to click on a component that is blocked by another modal component.
NamedValueSet &	getProperties () noexcept
	Returns the set of properties that belong to this component.
const NamedValueSet &	getProperties () const noexcept
	Returns the set of properties that belong to this component.
Colour	findColour (int colourID, bool inheritFromParent=false) const
	Looks for a colour that has been registered with the given colour ID number.
void	setColour (int colourID, Colour newColour)
	Registers a colour to be used for a particular purpose.
void	removeColour (int colourID)
	If a colour has been set with setColour(), this will remove it.
bool	isColourSpecified (int colourID) const
	Returns true if the specified colour ID has been explicitly set for this component using the setColour() method.
void	copyAllExplicitColoursTo (Component &target) const
	This looks for any colours that have been specified for this component, and copies them to the specified target component.
virtual void	colourChanged ()
	This method is called when a colour is changed by the setColour() method, or when the look-and-feel is changed by the setLookAndFeel() or sendLookAndFeelChanged() methods.
void *	getWindowHandle () const
	Returns the underlying native window handle for this component.
Positioner *	getPositioner () const noexcept
	Returns the Positioner object that has been set for this component.
void	setPositioner (Positioner *newPositioner)
	Sets a new Positioner object for this component.
void	setCachedComponentImage (CachedComponentImage *newCachedImage)
	Gives the component a CachedComponentImage that should be used to buffer its painting.
CachedComponentImage *	getCachedComponentImage () const noexcept
	Returns the object that was set by setCachedComponentImage().
void	setViewportIgnoreDragFlag (bool ignoreDrag) noexcept
	Sets a flag to indicate whether mouse drag events on this Component should be ignored when it is inside a Viewport with drag-to-scroll functionality enabled.
bool	getViewportIgnoreDragFlag () const noexcept
	Retrieves the current state of the Viewport drag-to-scroll functionality flag.
String	getTitle () const noexcept
	Returns the title text for this component.
void	setTitle (const String &newTitle)
	Sets the title for this component.
String	getDescription () const noexcept
	Returns the description for this component.
void	setDescription (const String &newDescription)
	Sets the description for this component.
String	getHelpText () const noexcept
	Returns the help text for this component.
void	setHelpText (const String &newHelpText)
	Sets the help text for this component.
void	setAccessible (bool shouldBeAccessible)
	Sets whether this component and its children are visible to accessibility clients.
bool	isAccessible () const noexcept
	Returns true if this component and its children are visible to accessibility clients.
AccessibilityHandler *	getAccessibilityHandler ()
	Returns the accessibility handler for this component, or nullptr if this component is not accessible.
void	invalidateAccessibilityHandler ()
	Invalidates the AccessibilityHandler that is currently being used for this component.
Public Member Functions inherited from MouseListener
virtual	~MouseListener ()=default
	Destructor.
Public Member Functions inherited from SettableTooltipClient
	~SettableTooltipClient () override=default
	Destructor.
String	getTooltip () override
	Returns the tooltip assigned to this object.
Public Member Functions inherited from TooltipClient
virtual	~TooltipClient ()=default
	Destructor.

Public Attributes
std::function< void()>	onClick
	You can assign a lambda to this callback object to have it called when the button is clicked.
std::function< void()>	onStateChange
	You can assign a lambda to this callback object to have it called when the button's state changes.

Protected Member Functions
	Button (const String &buttonName)
	Creates a button.
virtual void	clicked ()
	This method is called when the button has been clicked.
virtual void	clicked (const ModifierKeys &modifiers)
	This method is called when the button has been clicked.
virtual void	paintButton (Graphics &g, bool shouldDrawButtonAsHighlighted, bool shouldDrawButtonAsDown)=0
	Subclasses should override this to actually paint the button's contents.
virtual void	buttonStateChanged ()
	Called when the button's up/down/over state changes.
virtual void	internalClickCallback (const ModifierKeys &)
void	handleCommandMessage (int commandId) override
	Called to handle a command that was sent by postCommandMessage().
void	mouseEnter (const MouseEvent &) override
	Called when the mouse first enters a component.
void	mouseExit (const MouseEvent &) override
	Called when the mouse moves out of a component.
void	mouseDown (const MouseEvent &) override
	Called when a mouse button is pressed.
void	mouseDrag (const MouseEvent &) override
	Called when the mouse is moved while a button is held down.
void	mouseUp (const MouseEvent &) override
	Called when a mouse button is released.
bool	keyPressed (const KeyPress &) override
	Called when a key is pressed.
void	paint (Graphics &) override
	Components can override this method to draw their content.
void	parentHierarchyChanged () override
	Called to indicate that the component's parents have changed.
void	visibilityChanged () override
	Called when this component's visibility changes.
void	focusGained (FocusChangeType) override
	Called to indicate that this component has just acquired the keyboard focus.
void	focusLost (FocusChangeType) override
	Called to indicate that this component has just lost the keyboard focus.
void	enablementChanged () override
	Callback to indicate that this component has been enabled or disabled.
std::unique_ptr< AccessibilityHandler >	createAccessibilityHandler () override
	Override this method to return a custom AccessibilityHandler for this component.
virtual bool	keyStateChanged (bool isKeyDown)
	Called when a key is pressed or released.
Protected Member Functions inherited from SettableTooltipClient
	SettableTooltipClient ()=default

Additional Inherited Members
Static Public Member Functions inherited from Component
static float JUCE_CALLTYPE	getApproximateScaleFactorForComponent (const Component *targetComponent)
	Returns the approximate scale factor for a given component by traversing its parent hierarchy and applying each transform and finally scaling this by the global scale factor.
static Component *JUCE_CALLTYPE	getCurrentlyFocusedComponent () noexcept
	Returns the component that currently has the keyboard focus.
static void JUCE_CALLTYPE	unfocusAllComponents ()
	If any component has keyboard focus, this will defocus it.
static void JUCE_CALLTYPE	beginDragAutoRepeat (int millisecondsBetweenCallbacks)
	Ensures that a non-stop stream of mouse-drag events will be sent during the current mouse-drag operation.
static bool JUCE_CALLTYPE	isMouseButtonDownAnywhere () noexcept
	Returns true if a mouse button is currently down.
static int JUCE_CALLTYPE	getNumCurrentlyModalComponents () noexcept
	Returns the number of components that are currently in a modal state.
static Component *JUCE_CALLTYPE	getCurrentlyModalComponent (int index=0) noexcept
	Returns one of the components that are currently modal.

Detailed Description

A base class for buttons.

This contains all the logic for button behaviours such as enabling/disabling, responding to shortcut keystrokes, auto-repeating when held down, toggle-buttons and radio groups, etc.

See also

TextButton, DrawableButton, ToggleButton

Member Enumeration Documentation

ConnectedEdgeFlags

enum Button::ConnectedEdgeFlags

A combination of these flags are used by setConnectedEdges().

Enumerator
ConnectedOnLeft
ConnectedOnRight
ConnectedOnTop
ConnectedOnBottom

ButtonState

enum Button::ButtonState

Used by setState().

Enumerator
buttonNormal
buttonOver
buttonDown

Constructor & Destructor Documentation

Button()

Button::Button ( const String & buttonName )

explicitprotected

Creates a button.

Parameters

buttonName

the text to put in the button (the component's name is also initially set to this string, but these can be changed later using the setName() and setButtonText() methods)

~Button()

Button::~Button ( )

override

Destructor.

Member Function Documentation

setButtonText()

void Button::setButtonText

(

const String &

newText

)

Changes the button's text.

See also

getButtonText

getButtonText()

const String & Button::getButtonText

(

)

const

Returns the text displayed in the button.

See also

setButtonText

isDown()

bool Button::isDown ( ) const

noexcept

Returns true if the button is currently being held down.

See also

isOver

isOver()

bool Button::isOver ( ) const

noexcept

Returns true if the mouse is currently over the button.

This will be also be true if the button is being held down.

See also

isDown

setToggleable()

void Button::setToggleable

(

bool

shouldBeToggleable

)

Indicates that the button's on/off state is toggleable.

By default this is false, and will only be true for ToggleButtons, buttons that are a part of a radio button group, and buttons for which getClickingTogglesState() == true, however you can use this method to manually indicate that a button is toggleable.

This will present the button as toggleable to accessibility clients and add an accessible "toggle" action for the button that invokes setToggleState().

See also

ToggleButton, isToggleable, setToggleState, setClickingTogglesState, setRadioGroupId

isToggleable()

bool Button::isToggleable ( ) const

noexcept

Returns true if the button's on/off state is toggleable.

See also

setToggleable, setClickingTogglesState

setToggleState()

void Button::setToggleState	(	bool	shouldBeOn,
		NotificationType	notification )

A button has an on/off state associated with it, and this changes that.

By default buttons are 'off' and for simple buttons that you click to perform an action you won't change this. Toggle buttons, however will want to change their state when turned on or off.

Parameters

shouldBeOn	whether to set the button's toggle state to be on or off. If it's a member of a button group, this will always try to turn it on, and to turn off any other buttons in the group
notification	determines the behaviour if the value changes - this can invoke a synchronous call to clicked(), but sendNotificationAsync is not supported

See also

getToggleState, setRadioGroupId

getToggleState()

bool Button::getToggleState ( ) const

noexcept

Returns true if the button is 'on'.

By default buttons are 'off' and for simple buttons that you click to perform an action you won't change this. Toggle buttons, however will want to change their state when turned on or off.

See also

setToggleState

getToggleStateValue()

Value & Button::getToggleStateValue ( )

noexcept

Returns the Value object that represents the button's toggle state.

You can use this Value object to connect the button's state to external values or setters, either by taking a copy of the Value, or by using Value::referTo() to make it point to your own Value object.

See also

getToggleState, Value

setClickingTogglesState()

void Button::setClickingTogglesState ( bool shouldAutoToggleOnClick )

noexcept

This tells the button to automatically flip the toggle state when the button is clicked.

If set to true, then before the clicked() callback occurs, the toggle-state of the button is flipped. This will also cause isToggleable() to return true.

See also

isToggleable

getClickingTogglesState()

bool Button::getClickingTogglesState ( ) const

noexcept

Returns true if this button is set to be an automatic toggle-button.

This returns the last value that was passed to setClickingTogglesState().

setRadioGroupId()

void Button::setRadioGroupId	(	int	newGroupId,
		NotificationType	notification = sendNotification )

Enables the button to act as a member of a mutually-exclusive group of 'radio buttons'.

If the group ID is set to a non-zero number, then this button will act as part of a group of buttons with the same ID, only one of which can be 'on' at the same time. Note that when it's part of a group, clicking a toggle-button that's 'on' won't turn it off.

To find other buttons with the same ID, this button will search through its sibling components for ToggleButtons, so all the buttons for a particular group must be placed inside the same parent component.

Set the group ID back to zero if you want it to act as a normal toggle button again.

The notification argument lets you specify how other buttons should react to being turned on or off in response to this call.

See also

getRadioGroupId

getRadioGroupId()

int Button::getRadioGroupId ( ) const

noexcept

Returns the ID of the group to which this button belongs.

(See setRadioGroupId() for an explanation of this).

addListener()

void Button::addListener

(

Listener *

newListener

)

Registers a listener to receive events when this button's state changes.

If the listener is already registered, this will not register it again.

See also

removeListener

removeListener()

void Button::removeListener

(

Listener *

listener

)

Removes a previously-registered button listener.

See also

addListener

triggerClick()

virtual void Button::triggerClick ( )

virtual

Causes the button to act as if it's been clicked.

This will asynchronously make the button draw itself going down and up, and will then call back the clicked() method as if mouse was clicked on it.

See also

clicked

setCommandToTrigger()

void Button::setCommandToTrigger	(	ApplicationCommandManager *	commandManagerToUse,
		CommandID	commandID,
		bool	generateTooltip )

Sets a command ID for this button to automatically invoke when it's clicked.

When the button is pressed, it will use the given manager to trigger the command ID.

Obviously be careful that the ApplicationCommandManager doesn't get deleted before this button is. To disable the command triggering, call this method and pass nullptr as the command manager.

If generateTooltip is true, then the button's tooltip will be automatically generated based on the name of this command and its current shortcut key.

See also

addShortcut, getCommandID

getCommandID()

CommandID Button::getCommandID ( ) const

noexcept

Returns the command ID that was set by setCommandToTrigger().

addShortcut()

void Button::addShortcut

(

const KeyPress &

)

Assigns a shortcut key to trigger the button.

The button registers itself with its top-level parent component for keypresses.

Note that a different way of linking buttons to keypresses is by using the setCommandToTrigger() method to invoke a command.

See also

clearShortcuts

clearShortcuts()

void Button::clearShortcuts

(

)

Removes all key shortcuts that had been set for this button.

See also

addShortcut

isRegisteredForShortcut()

bool Button::isRegisteredForShortcut

(

const KeyPress &

)

const

Returns true if the given keypress is a shortcut for this button.

See also

addShortcut

setRepeatSpeed()

void Button::setRepeatSpeed ( int initialDelayInMillisecs, int repeatDelayInMillisecs, int minimumDelayInMillisecs = -1 )

noexcept

Sets an auto-repeat speed for the button when it is held down.

(Auto-repeat is disabled by default).

Parameters

initialDelayInMillisecs	how long to wait after the mouse is pressed before triggering the next click. If this is zero, auto-repeat is disabled
repeatDelayInMillisecs	the frequently subsequent repeated clicks should be triggered
minimumDelayInMillisecs	if this is greater than 0, the auto-repeat speed will get faster, the longer the button is held down, up to the minimum interval specified here

setTriggeredOnMouseDown()

void Button::setTriggeredOnMouseDown ( bool isTriggeredOnMouseDown )

noexcept

Sets whether the button click should happen when the mouse is pressed or released.

By default the button is only considered to have been clicked when the mouse is released, but setting this to true will make it call the clicked() method as soon as the button is pressed.

This is useful if the button is being used to show a pop-up menu, as it allows the click to be used as a drag onto the menu.

getTriggeredOnMouseDown()

bool Button::getTriggeredOnMouseDown ( ) const

noexcept

Returns whether the button click happens when the mouse is pressed or released.

See also

setTriggeredOnMouseDown

getMillisecondsSinceButtonDown()

uint32 Button::getMillisecondsSinceButtonDown ( ) const

noexcept

Returns the number of milliseconds since the last time the button went into the 'down' state.

setTooltip()

void Button::setTooltip ( const String & newTooltip )

overridevirtual

Sets the tooltip for this button.

See also

TooltipClient, TooltipWindow

Reimplemented from SettableTooltipClient.

setConnectedEdges()

void Button::setConnectedEdges

(

int

connectedEdgeFlags

)

Hints about which edges of the button might be connected to adjoining buttons.

The value passed in is a bitwise combination of any of the values in the ConnectedEdgeFlags enum.

E.g. if you are placing two buttons adjacent to each other, you could use this to indicate which edges are touching, and the LookAndFeel might choose to drawn them without rounded corners on the edges that connect. It's only a hint, so the LookAndFeel can choose to ignore it if it's not relevant for this type of button.

getConnectedEdgeFlags()

int Button::getConnectedEdgeFlags ( ) const

noexcept

Returns the set of flags passed into setConnectedEdges().

isConnectedOnLeft()

bool Button::isConnectedOnLeft ( ) const

noexcept

Indicates whether the button adjoins another one on its left edge.

See also

setConnectedEdges

isConnectedOnRight()

bool Button::isConnectedOnRight ( ) const

noexcept

Indicates whether the button adjoins another one on its right edge.

See also

setConnectedEdges

isConnectedOnTop()

bool Button::isConnectedOnTop ( ) const

noexcept

Indicates whether the button adjoins another one on its top edge.

See also

setConnectedEdges

isConnectedOnBottom()

bool Button::isConnectedOnBottom ( ) const

noexcept

Indicates whether the button adjoins another one on its bottom edge.

See also

setConnectedEdges

setState()

void Button::setState

(

ButtonState

newState

)

Can be used to force the button into a particular state.

This only changes the button's appearance, it won't trigger a click, or stop any mouse-clicks from happening.

The state that you set here will only last until it is automatically changed when the mouse enters or exits the button, or the mouse-button is pressed or released.

getState()

ButtonState Button::getState ( ) const

noexcept

Returns the button's current over/down/up state.

clicked() [1/2]

virtual void Button::clicked ( )

protectedvirtual

This method is called when the button has been clicked.

Subclasses can override this to perform whatever actions they need to do. In general, you wouldn't use this method to receive clicks, but should get your callbacks by attaching a std::function to the onClick callback, or adding a Button::Listener.

See also

triggerClick, onClick

Reimplemented in HyperlinkButton.

clicked() [2/2]

virtual void Button::clicked ( const ModifierKeys & modifiers )

protectedvirtual

This method is called when the button has been clicked.

By default it just calls clicked(), but you might want to override it to handle things like clicking when a modifier key is pressed, etc.

See also

ModifierKeys

Reimplemented in TabBarButton.

paintButton()

virtual void Button::paintButton ( Graphics & g, bool shouldDrawButtonAsHighlighted, bool shouldDrawButtonAsDown )

protectedpure virtual

Subclasses should override this to actually paint the button's contents.

It's better to use this than the paint method, because it gives you information about the over/down state of the button.

Parameters

g	the graphics context to use
shouldDrawButtonAsHighlighted	true if the button is either in the 'over' or 'down' state
shouldDrawButtonAsDown	true if the button should be drawn in the 'down' position

Implemented in ToolbarItemComponent, ArrowButton, DrawableButton, HyperlinkButton, ImageButton, ShapeButton, TextButton, ToggleButton, and TabBarButton.

buttonStateChanged()

virtual void Button::buttonStateChanged ( )

protectedvirtual

Called when the button's up/down/over state changes.

Subclasses can override this if they need to do something special when the button goes up or down.

See also

isDown, isOver

Reimplemented in DrawableButton, and ToolbarButton.

internalClickCallback()

virtual void Button::internalClickCallback ( const ModifierKeys & )

protectedvirtual

handleCommandMessage()

void Button::handleCommandMessage ( int commandId )

overrideprotectedvirtual

Called to handle a command that was sent by postCommandMessage().

This is called by the message thread when a command message arrives, and the component can override this method to process it in any way it needs to.

See also

postCommandMessage

Reimplemented from Component.

mouseEnter()

void Button::mouseEnter ( const MouseEvent & event )

overrideprotectedvirtual

Called when the mouse first enters a component.

If the mouse button isn't pressed and the mouse moves into a component, this will be called to let the component react to this.

When the mouse button is pressed and held down while being moved in or out of a component, no mouseEnter or mouseExit callbacks are made - only mouseDrag messages are sent to the component that the mouse was originally clicked on, until the button is released.

Parameters

event

details about the position and status of the mouse event, including the source component in which it occurred

See also

mouseExit, mouseDrag, mouseMove, contains

Reimplemented from MouseListener.

mouseExit()

void Button::mouseExit ( const MouseEvent & event )

overrideprotectedvirtual

Called when the mouse moves out of a component.

This will be called when the mouse moves off the edge of this component.

If the mouse button was pressed, and it was then dragged off the edge of the component and released, then this callback will happen when the button is released, after the mouseUp callback.

Parameters

event

details about the position and status of the mouse event, including the source component in which it occurred

See also

mouseEnter, mouseDrag, mouseMove, contains

Reimplemented from MouseListener.

mouseDown()

void Button::mouseDown ( const MouseEvent & event )

overrideprotectedvirtual

Called when a mouse button is pressed.

The MouseEvent object passed in contains lots of methods for finding out which button was pressed, as well as which modifier keys (e.g. shift, ctrl) were held down at the time.

Once a button is held down, the mouseDrag method will be called when the mouse moves, until the button is released.

Parameters

event

details about the position and status of the mouse event, including the source component in which it occurred

See also

mouseUp, mouseDrag, mouseDoubleClick, contains

Reimplemented from MouseListener.

mouseDrag()

void Button::mouseDrag ( const MouseEvent & event )

overrideprotectedvirtual

Called when the mouse is moved while a button is held down.

When a mouse button is pressed inside a component, that component receives mouseDrag callbacks each time the mouse moves, even if the mouse strays outside the component's bounds.

Parameters

event

details about the position and status of the mouse event, including the source component in which it occurred

See also

mouseDown, mouseUp, mouseMove, contains, setDragRepeatInterval

Reimplemented from MouseListener.

mouseUp()

void Button::mouseUp ( const MouseEvent & event )

overrideprotectedvirtual

Called when a mouse button is released.

A mouseUp callback is sent to the component in which a button was pressed even if the mouse is actually over a different component when the button is released.

The MouseEvent object passed in contains lots of methods for finding out which buttons were down just before they were released.

Parameters

event

details about the position and status of the mouse event, including the source component in which it occurred

See also

mouseDown, mouseDrag, mouseDoubleClick, contains

Reimplemented from MouseListener.

keyPressed()

bool Button::keyPressed ( const KeyPress & key )

overrideprotectedvirtual

Called when a key is pressed.

When a key is pressed, the component that has the keyboard focus will have this method called. Remember that a component will only be given the focus if its setWantsKeyboardFocus() method has been used to enable this.

If your implementation returns true, the event will be consumed and not passed on to any other listeners. If it returns false, the key will be passed to any KeyListeners that have been registered with this component. As soon as one of these returns true, the process will stop, but if they all return false, the event will be passed upwards to this component's parent, and so on.

The default implementation of this method does nothing and returns false.

See also

keyStateChanged, getCurrentlyFocusedComponent, addKeyListener

Reimplemented from Component.

References Component::keyStateChanged().

paint()

void Button::paint ( Graphics & g )

overrideprotectedvirtual

Components can override this method to draw their content.

The paint() method gets called when a region of a component needs redrawing, either because the component's repaint() method has been called, or because something has happened on the screen that means a section of a window needs to be redrawn.

Any child components will draw themselves over whatever this method draws. If you need to paint over the top of your child components, you can also implement the paintOverChildren() method to do this.

If you want to cause a component to redraw itself, this is done asynchronously - calling the repaint() method marks a region of the component as "dirty", and the paint() method will automatically be called sometime later, by the message thread, to paint any bits that need refreshing. In JUCE (and almost all modern UI frameworks), you never redraw something synchronously.

You should never need to call this method directly - to take a snapshot of the component you could use createComponentSnapshot() or paintEntireComponent().

Parameters

g	the graphics context that must be used to do the drawing operations.

See also

repaint, paintOverChildren, Graphics

Reimplemented from Component.

parentHierarchyChanged()

void Button::parentHierarchyChanged ( )

overrideprotectedvirtual

Called to indicate that the component's parents have changed.

When a component is added or removed from its parent, this method will be called on all of its children (recursively - so all children of its children will also be called as well).

Subclasses can override this if they need to react to this in some way.

See also

getParentComponent, isShowing, ComponentListener::componentParentHierarchyChanged

Reimplemented from Component.

visibilityChanged()

void Button::visibilityChanged ( )

overrideprotectedvirtual

Called when this component's visibility changes.

See also

setVisible, isVisible

Reimplemented from Component.

focusGained()

void Button::focusGained ( FocusChangeType cause )

overrideprotectedvirtual

Called to indicate that this component has just acquired the keyboard focus.

See also

focusLost, setWantsKeyboardFocus, getCurrentlyFocusedComponent, hasKeyboardFocus

Reimplemented from Component.

focusLost()

void Button::focusLost ( FocusChangeType cause )

overrideprotectedvirtual

Called to indicate that this component has just lost the keyboard focus.

See also

focusGained, setWantsKeyboardFocus, getCurrentlyFocusedComponent, hasKeyboardFocus

Reimplemented from Component.

enablementChanged()

void Button::enablementChanged ( )

overrideprotectedvirtual

Callback to indicate that this component has been enabled or disabled.

This can be triggered by one of the component's parent components being enabled or disabled, as well as changes to the component itself.

The default implementation of this method does nothing; your class may wish to repaint itself or something when this happens.

See also

setEnabled, isEnabled

Reimplemented from Component.

Reimplemented in DrawableButton, and ToolbarButton.

createAccessibilityHandler()

std::unique_ptr< AccessibilityHandler > Button::createAccessibilityHandler ( )

overrideprotectedvirtual

Override this method to return a custom AccessibilityHandler for this component.

The default implementation creates and returns a AccessibilityHandler object with an unspecified role, meaning that it will be visible to accessibility clients but without a specific role, action callbacks or interfaces. To control how accessibility clients see and interact with your component subclass AccessibilityHandler, implement the desired behaviours, and return an instance of it from this method in your component subclass.

The accessibility handler you return here is guaranteed to be destroyed before its Component, so it's safe to store and use a reference back to the Component inside the AccessibilityHandler if necessary.

This function should rarely be called directly. If you need to query a component's accessibility handler, it's normally better to call getAccessibilityHandler(). The exception to this rule is derived implementations of createAccessibilityHandler(), which may find it useful to call the base class implementation, and then wrap or modify the result.

See also

getAccessibilityHandler

Reimplemented from Component.

Reimplemented in HyperlinkButton, ToggleButton, and ToolbarItemComponent.

keyStateChanged()

virtual bool Component::keyStateChanged ( bool isKeyDown )

protectedvirtual

Called when a key is pressed or released.

Whenever a key on the keyboard is pressed or released (including modifier keys like shift and ctrl), this method will be called on the component that currently has the keyboard focus. Remember that a component will only be given the focus if its setWantsKeyboardFocus() method has been used to enable this.

If your implementation returns true, the event will be consumed and not passed on to any other listeners. If it returns false, then any KeyListeners that have been registered with this component will have their keyStateChanged methods called. As soon as one of these returns true, the process will stop, but if they all return false, the event will be passed upwards to this component's parent, and so on.

The default implementation of this method does nothing and returns false.

To find out which keys are up or down at any time, see the KeyPress::isKeyCurrentlyDown() method.

Parameters

isKeyDown

true if a key has been pressed; false if it has been released

See also

keyPressed, KeyPress, getCurrentlyFocusedComponent, addKeyListener

Reimplemented from Component.

Member Data Documentation

onClick

std::function<void()> Button::onClick

You can assign a lambda to this callback object to have it called when the button is clicked.

onStateChange

std::function<void()> Button::onStateChange

You can assign a lambda to this callback object to have it called when the button's state changes.

---

The documentation for this class was generated from the following file:

• juce_Button.h