ComboBox Class Reference

A component that lets the user choose from a drop-down list of choices. More...

#include <juce_ComboBox.h>

Inheritance diagram for ComboBox:

Classes
class	Listener
	A class for receiving events from a ComboBox. More...
struct	LookAndFeelMethods
	This abstract base class is implemented by LookAndFeel classes to provide ComboBox functionality. More...

Public Types
enum	ColourIds {   backgroundColourId = 0x1000b00 , textColourId = 0x1000a00 , outlineColourId = 0x1000c00 , buttonColourId = 0x1000d00 ,   arrowColourId = 0x1000e00 , focusedOutlineColourId = 0x1000f00 }
	A set of colour IDs to use to change the colour of various aspects of the combo box. 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
	ComboBox (const String &componentName={})
	Creates a combo-box.
	~ComboBox () override
	Destructor.
void	setEditableText (bool isEditable)
	Sets whether the text in the combo-box is editable.
bool	isTextEditable () const noexcept
	Returns true if the text is directly editable.
void	setJustificationType (Justification justification)
	Sets the style of justification to be used for positioning the text.
Justification	getJustificationType () const noexcept
	Returns the current justification for the text box.
void	addItem (const String &newItemText, int newItemId)
	Adds an item to be shown in the drop-down list.
void	addItemList (const StringArray &items, int firstItemIdOffset)
	Adds an array of items to the drop-down list.
void	addSeparator ()
	Adds a separator line to the drop-down list.
void	addSectionHeading (const String &headingName)
	Adds a heading to the drop-down list, so that you can group the items into different sections.
void	setItemEnabled (int itemId, bool shouldBeEnabled)
	This allows items in the drop-down list to be selectively disabled.
bool	isItemEnabled (int itemId) const noexcept
	Returns true if the given item is enabled.
void	changeItemText (int itemId, const String &newText)
	Changes the text for an existing item.
void	clear (NotificationType notification=sendNotificationAsync)
	Removes all the items from the drop-down list.
int	getNumItems () const noexcept
	Returns the number of items that have been added to the list.
String	getItemText (int index) const
	Returns the text for one of the items in the list.
int	getItemId (int index) const noexcept
	Returns the ID for one of the items in the list.
int	indexOfItemId (int itemId) const noexcept
	Returns the index in the list of a particular item ID.
int	getSelectedId () const noexcept
	Returns the ID of the item that's currently shown in the box.
Value &	getSelectedIdAsValue ()
	Returns a Value object that can be used to get or set the selected item's ID.
void	setSelectedId (int newItemId, NotificationType notification=sendNotificationAsync)
	Sets one of the items to be the current selection.
int	getSelectedItemIndex () const
	Returns the index of the item that's currently shown in the box.
void	setSelectedItemIndex (int newItemIndex, NotificationType notification=sendNotificationAsync)
	Sets one of the items to be the current selection.
String	getText () const
	Returns the text that is currently shown in the combo-box's text field.
void	setText (const String &newText, NotificationType notification=sendNotificationAsync)
	Sets the contents of the combo-box's text field.
void	showEditor ()
	Programmatically opens the text editor to allow the user to edit the current item.
virtual void	showPopup ()
	Pops up the combo box's list.
void	hidePopup ()
	Hides the combo box's popup list, if it's currently visible.
bool	isPopupActive () const noexcept
	Returns true if the popup menu is currently being shown.
PopupMenu *	getRootMenu () noexcept
	Returns the PopupMenu object associated with the ComboBox.
const PopupMenu *	getRootMenu () const noexcept
	Returns the PopupMenu object associated with the ComboBox.
void	addListener (Listener *listener)
	Registers a listener that will be called when the box's content changes.
void	removeListener (Listener *listener)
	Deregisters a previously-registered listener.
void	setTextWhenNothingSelected (const String &newMessage)
	Sets a message to display when there is no item currently selected.
String	getTextWhenNothingSelected () const
	Returns the text that is shown when no item is selected.
void	setTextWhenNoChoicesAvailable (const String &newMessage)
	Sets the message to show when there are no items in the list, and the user clicks on the drop-down box.
String	getTextWhenNoChoicesAvailable () const
	Returns the text shown when no items have been added to the list.
void	setTooltip (const String &newTooltip) override
	Gives the ComboBox a tooltip.
void	setScrollWheelEnabled (bool enabled) noexcept
	This can be used to allow the scroll-wheel to nudge the chosen item.
void	enablementChanged () override
	Callback to indicate that this component has been enabled or disabled.
void	colourChanged () override
	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	focusGained (Component::FocusChangeType) override
	Called to indicate that this component has just acquired the keyboard focus.
void	focusLost (Component::FocusChangeType) override
	Called to indicate that this component has just lost the keyboard focus.
void	handleAsyncUpdate () override
	Called back to do whatever your class needs to do.
String	getTooltip () override
	Returns the string that this object wants to show as its tooltip.
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.
void	mouseWheelMove (const MouseEvent &, const MouseWheelDetails &) override
	Called when the mouse-wheel is moved.
void	lookAndFeelChanged () override
	Called to let the component react to a change in the look-and-feel setting.
void	paint (Graphics &) override
	Components can override this method to draw their content.
void	resized () override
	Called when this component's size has been changed.
bool	keyStateChanged (bool) override
	Called when a key is pressed or released.
bool	keyPressed (const KeyPress &) override
	Called when a key is pressed.
void	valueChanged (Value &) override
	Called when a Value object is changed.
void	parentHierarchyChanged () override
	Called to indicate that the component's parents have changed.
std::unique_ptr< AccessibilityHandler >	createAccessibilityHandler () override
	Override this method to return a custom AccessibilityHandler for this component.
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.
virtual void	visibilityChanged ()
	Called when this component's visibility changes.
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.
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	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.
virtual void	handleCommandMessage (int commandId)
	Called to handle a command that was sent by postCommandMessage().
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.
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 Member Functions inherited from Value::Listener
	Listener ()=default
virtual	~Listener ()=default

Public Attributes
std::function< void()>	onChange
	You can assign a lambda to this callback object to have it called when the selected ID is changed.

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.
Protected Member Functions inherited from SettableTooltipClient
	SettableTooltipClient ()=default

Detailed Description

A component that lets the user choose from a drop-down list of choices.

The combo-box has a list of text strings, each with an associated id number, that will be shown in the drop-down list when the user clicks on the component.

The currently selected choice is displayed in the combo-box, and this can either be read-only text, or editable.

To find out when the user selects a different item or edits the text, you can assign a lambda to the onChange member, or register a ComboBox::Listener to receive callbacks.

Member Enumeration Documentation

ColourIds

enum ComboBox::ColourIds

A set of colour IDs to use to change the colour of various aspects of the combo box.

These constants can be used either via the Component::setColour(), or LookAndFeel::setColour() methods.

To change the colours of the menu that pops up, you can set the colour IDs in PopupMenu::ColourIDs.

See also

Component::setColour, Component::findColour, LookAndFeel::setColour, LookAndFeel::findColour

Enumerator
backgroundColourId	The background colour to fill the box with.
textColourId	The colour for the text in the box.
outlineColourId	The colour for an outline around the box.
buttonColourId	The base colour for the button (a LookAndFeel class will probably use variations on this).
arrowColourId	The colour for the arrow shape that pops up the menu.
focusedOutlineColourId	The colour that will be used to draw a box around the edge of the component when it has focus.

Constructor & Destructor Documentation

ComboBox()

ComboBox::ComboBox ( const String & componentName = {} )

explicit

Creates a combo-box.

On construction, the text field will be empty, so you should call the setSelectedId() or setText() method to choose the initial value before displaying it.

Parameters

componentName

the name to set for the component (see Component::setName())

~ComboBox()

ComboBox::~ComboBox ( )

override

Destructor.

Member Function Documentation

setEditableText()

void ComboBox::setEditableText

(

bool

isEditable

)

Sets whether the text in the combo-box is editable.

The default state for a new ComboBox is non-editable, and can only be changed by choosing from the drop-down list.

isTextEditable()

bool ComboBox::isTextEditable ( ) const

noexcept

Returns true if the text is directly editable.

See also

setEditableText

setJustificationType()

void ComboBox::setJustificationType

(

Justification

justification

)

Sets the style of justification to be used for positioning the text.

The default is Justification::centredLeft. The text is displayed using a Label component inside the ComboBox.

getJustificationType()

Justification ComboBox::getJustificationType ( ) const

noexcept

Returns the current justification for the text box.

See also

setJustificationType

addItem()

void ComboBox::addItem	(	const String &	newItemText,
		int	newItemId )

Adds an item to be shown in the drop-down list.

Parameters

newItemText	the text of the item to show in the list
newItemId	an associated ID number that can be set or retrieved - see getSelectedId() and setSelectedId(). Note that this value can not be 0!

See also

setItemEnabled, addSeparator, addSectionHeading, getNumItems, getItemText, getItemId

addItemList()

void ComboBox::addItemList	(	const StringArray &	items,
		int	firstItemIdOffset )

Adds an array of items to the drop-down list.

The item ID of each item will be its index in the StringArray + firstItemIdOffset.

addSeparator()

void ComboBox::addSeparator

(

)

Adds a separator line to the drop-down list.

This is like adding a separator to a popup menu. See PopupMenu::addSeparator().

addSectionHeading()

void ComboBox::addSectionHeading

(

const String &

headingName

)

Adds a heading to the drop-down list, so that you can group the items into different sections.

The headings are indented slightly differently to set them apart from the items on the list, and obviously can't be selected. You might want to add separators between your sections too.

See also

addItem, addSeparator

setItemEnabled()

void ComboBox::setItemEnabled	(	int	itemId,
		bool	shouldBeEnabled )

This allows items in the drop-down list to be selectively disabled.

When you add an item, it's enabled by default, but you can call this method to change its status.

If you disable an item which is already selected, this won't change the current selection - it just stops the user choosing that item from the list.

isItemEnabled()

bool ComboBox::isItemEnabled ( int itemId ) const

noexcept

Returns true if the given item is enabled.

changeItemText()

void ComboBox::changeItemText	(	int	itemId,
		const String &	newText )

Changes the text for an existing item.

clear()

void ComboBox::clear

(

NotificationType

notification = sendNotificationAsync

)

Removes all the items from the drop-down list.

If this call causes the content to be cleared, and a change-message will be broadcast according to the notification parameter.

See also

addItem, getNumItems

getNumItems()

int ComboBox::getNumItems ( ) const

noexcept

Returns the number of items that have been added to the list.

Note that this doesn't include headers or separators.

getItemText()

String ComboBox::getItemText

(

int

index

)

const

Returns the text for one of the items in the list.

Note that this doesn't include headers or separators.

Parameters

index

the item's index from 0 to (getNumItems() - 1)

getItemId()

int ComboBox::getItemId ( int index ) const

noexcept

Returns the ID for one of the items in the list.

Note that this doesn't include headers or separators.

Parameters

index

the item's index from 0 to (getNumItems() - 1)

indexOfItemId()

int ComboBox::indexOfItemId ( int itemId ) const

noexcept

Returns the index in the list of a particular item ID.

If no such ID is found, this will return -1.

getSelectedId()

int ComboBox::getSelectedId ( ) const

noexcept

Returns the ID of the item that's currently shown in the box.

If no item is selected, or if the text is editable and the user has entered something which isn't one of the items in the list, then this will return 0.

See also

setSelectedId, getSelectedItemIndex, getText

getSelectedIdAsValue()

Value & ComboBox::getSelectedIdAsValue

(

)

Returns a Value object that can be used to get or set the selected item's ID.

You can call Value::referTo() on this object to make the combo box control another Value object.

setSelectedId()

void ComboBox::setSelectedId	(	int	newItemId,
		NotificationType	notification = sendNotificationAsync )

Sets one of the items to be the current selection.

This will set the ComboBox's text to that of the item that matches this ID.

Parameters

newItemId	the new item to select
notification	determines the type of change notification that will be sent to listeners if the value changes

See also

getSelectedId, setSelectedItemIndex, setText

getSelectedItemIndex()

int ComboBox::getSelectedItemIndex

(

)

const

Returns the index of the item that's currently shown in the box.

If no item is selected, or if the text is editable and the user has entered something which isn't one of the items in the list, then this will return -1.

See also

setSelectedItemIndex, getSelectedId, getText

setSelectedItemIndex()

void ComboBox::setSelectedItemIndex	(	int	newItemIndex,
		NotificationType	notification = sendNotificationAsync )

Sets one of the items to be the current selection.

This will set the ComboBox's text to that of the item at the given index in the list.

Parameters

newItemIndex	the new item to select
notification	determines the type of change notification that will be sent to listeners if the value changes

See also

getSelectedItemIndex, setSelectedId, setText

getText()

String ComboBox::getText

(

)

const

Returns the text that is currently shown in the combo-box's text field.

If the ComboBox has editable text, then this text may have been edited by the user; otherwise it will be one of the items from the list, or possibly an empty string if nothing was selected.

See also

setText, getSelectedId, getSelectedItemIndex

setText()

void ComboBox::setText	(	const String &	newText,
		NotificationType	notification = sendNotificationAsync )

Sets the contents of the combo-box's text field.

The text passed-in will be set as the current text regardless of whether it is one of the items in the list. If the current text isn't one of the items, then getSelectedId() will return 0, otherwise it will return the appropriate ID.

Parameters

newText	the text to select
notification	determines the type of change notification that will be sent to listeners if the text changes

See also

getText

showEditor()

void ComboBox::showEditor

(

)

Programmatically opens the text editor to allow the user to edit the current item.

This is the same effect as when the box is clicked-on.

See also

Label::showEditor();

showPopup()

virtual void ComboBox::showPopup ( )

virtual

Pops up the combo box's list.

This is virtual so that you can override it with your own custom popup mechanism if you need some really unusual behaviour.

hidePopup()

void ComboBox::hidePopup

(

)

Hides the combo box's popup list, if it's currently visible.

isPopupActive()

bool ComboBox::isPopupActive ( ) const

noexcept

Returns true if the popup menu is currently being shown.

getRootMenu() [1/2]

PopupMenu * ComboBox::getRootMenu ( )

noexcept

Returns the PopupMenu object associated with the ComboBox.

Can be useful for adding sub-menus to the ComboBox standard PopupMenu

getRootMenu() [2/2]

const PopupMenu * ComboBox::getRootMenu ( ) const

noexcept

Returns the PopupMenu object associated with the ComboBox.

addListener()

void ComboBox::addListener

(

Listener *

listener

)

Registers a listener that will be called when the box's content changes.

removeListener()

void ComboBox::removeListener

(

Listener *

listener

)

Deregisters a previously-registered listener.

setTextWhenNothingSelected()

void ComboBox::setTextWhenNothingSelected

(

const String &

newMessage

)

Sets a message to display when there is no item currently selected.

See also

getTextWhenNothingSelected

getTextWhenNothingSelected()

String ComboBox::getTextWhenNothingSelected

(

)

const

Returns the text that is shown when no item is selected.

See also

setTextWhenNothingSelected

setTextWhenNoChoicesAvailable()

void ComboBox::setTextWhenNoChoicesAvailable

(

const String &

newMessage

)

Sets the message to show when there are no items in the list, and the user clicks on the drop-down box.

By default it just says "no choices", but this lets you change it to something more meaningful.

getTextWhenNoChoicesAvailable()

String ComboBox::getTextWhenNoChoicesAvailable

(

)

const

Returns the text shown when no items have been added to the list.

See also

setTextWhenNoChoicesAvailable

setTooltip()

void ComboBox::setTooltip ( const String & newTooltip )

overridevirtual

Gives the ComboBox a tooltip.

Reimplemented from SettableTooltipClient.

setScrollWheelEnabled()

void ComboBox::setScrollWheelEnabled ( bool enabled )

noexcept

This can be used to allow the scroll-wheel to nudge the chosen item.

By default it's disabled, and I'd recommend leaving it disabled if there's any chance that the control might be inside a scrollable list or viewport.

enablementChanged()

void ComboBox::enablementChanged ( )

overridevirtual

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.

colourChanged()

void ComboBox::colourChanged ( )

overridevirtual

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.

See also

setColour, findColour, setLookAndFeel, sendLookAndFeelChanged

Reimplemented from Component.

focusGained()

void ComboBox::focusGained ( Component::FocusChangeType cause )

overridevirtual

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

See also

focusLost, setWantsKeyboardFocus, getCurrentlyFocusedComponent, hasKeyboardFocus

Reimplemented from Component.

focusLost()

void ComboBox::focusLost ( Component::FocusChangeType cause )

overridevirtual

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

See also

focusGained, setWantsKeyboardFocus, getCurrentlyFocusedComponent, hasKeyboardFocus

Reimplemented from Component.

handleAsyncUpdate()

void ComboBox::handleAsyncUpdate ( )

overridevirtual

Called back to do whatever your class needs to do.

This method is called by the message thread at the next convenient time after the triggerAsyncUpdate() method has been called.

Implements AsyncUpdater.

getTooltip()

String ComboBox::getTooltip ( )

overridevirtual

Returns the string that this object wants to show as its tooltip.

Implements TooltipClient.

References label.

mouseDown()

void ComboBox::mouseDown ( const MouseEvent & event )

overridevirtual

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 ComboBox::mouseDrag ( const MouseEvent & event )

overridevirtual

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 ComboBox::mouseUp ( const MouseEvent & event )

overridevirtual

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.

mouseWheelMove()

void ComboBox::mouseWheelMove ( const MouseEvent & event, const MouseWheelDetails & wheel )

overridevirtual

Called when the mouse-wheel is moved.

This callback is sent to the component that the mouse is over when the wheel is moved.

If not overridden, a component will forward this message to its parent, so that parent components can collect mouse-wheel messages that happen to child components which aren't interested in them.

Parameters

event	details about the mouse event
wheel	details about the wheel movement

Reimplemented from MouseListener.

lookAndFeelChanged()

void ComboBox::lookAndFeelChanged ( )

overridevirtual

Called to let the component react to a change in the look-and-feel setting.

When the look-and-feel is changed for a component, this method, repaint(), and colourChanged() are called on the original component and all its children recursively.

It can also be triggered manually by the sendLookAndFeelChange() method, in case an application uses a LookAndFeel class that might have changed internally.

See also

sendLookAndFeelChange, getLookAndFeel

Reimplemented from Component.

paint()

void ComboBox::paint ( Graphics & g )

overridevirtual

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.

resized()

void ComboBox::resized ( )

overridevirtual

Called when this component's size has been changed.

A component can implement this method to do things such as laying out its child components when its width or height changes.

The method is called synchronously as a result of the setBounds or setSize methods, so repeatedly changing a components size will repeatedly call its resized method (unlike things like repainting, where multiple calls to repaint are coalesced together).

If the component is a top-level window on the desktop, its size could also be changed by operating-system factors beyond the application's control.

See also

moved, setSize

Reimplemented from Component.

keyStateChanged()

bool ComboBox::keyStateChanged ( bool isKeyDown )

overridevirtual

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.

keyPressed()

bool ComboBox::keyPressed ( const KeyPress & key )

overridevirtual

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.

valueChanged()

void ComboBox::valueChanged ( Value & value )

overridevirtual

Called when a Value object is changed.

Note that the Value object passed as a parameter may not be exactly the same object that you registered the listener with - it might be a copy that refers to the same underlying ValueSource. To find out, you can call Value::refersToSameSourceAs().

Implements Value::Listener.

parentHierarchyChanged()

void ComboBox::parentHierarchyChanged ( )

overridevirtual

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.

createAccessibilityHandler()

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

overridevirtual

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.

Member Data Documentation

onChange

std::function<void()> ComboBox::onChange

You can assign a lambda to this callback object to have it called when the selected ID is changed.

---

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

• juce_ComboBox.h