KeyboardComponentBase Class Reference

A base class for drawing a custom MIDI keyboard component. More...

#include <juce_KeyboardComponentBase.h>

Inheritance diagram for KeyboardComponentBase:

Classes
struct	NoteAndVelocity
	This structure is returned by the getNoteAndVelocityAtPosition() method. More...

Public Types
enum	Orientation { horizontalKeyboard , verticalKeyboardFacingLeft , verticalKeyboardFacingRight }
	The direction of the keyboard. More...
enum	ColourIds { upDownButtonBackgroundColourId = 0x1004000 , upDownButtonArrowColourId = 0x1004001 }
	Colour IDs to use to change the colour of the octave scroll buttons. More...
Public Types inherited from Component
enum class	WindowControlKind {   client , caption , minimise , maximise ,   close , sizeTop , sizeLeft , sizeRight ,   sizeBottom , sizeTopLeft , sizeTopRight , sizeBottomLeft ,   sizeBottomRight }
	Types of control that are commonly found in windows, especially title-bars. More...
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
	KeyboardComponentBase (Orientation orientation)
	Constructor.
	~KeyboardComponentBase () override=default
	Destructor.
void	setKeyWidth (float widthInPixels)
	Changes the width used to draw the white keys.
float	getKeyWidth () const noexcept
	Returns the width that was set by setKeyWidth().
void	setScrollButtonWidth (int widthInPixels)
	Changes the width used to draw the buttons that scroll the keyboard up/down in octaves.
int	getScrollButtonWidth () const noexcept
	Returns the width that was set by setScrollButtonWidth().
void	setOrientation (Orientation newOrientation)
	Changes the keyboard's current direction.
Orientation	getOrientation () const noexcept
	Returns the keyboard's current direction.
bool	isHorizontal () const noexcept
	Returns true if the keyboard's orientation is horizontal.
void	setAvailableRange (int lowestNote, int highestNote)
	Sets the range of midi notes that the keyboard will be limited to.
int	getRangeStart () const noexcept
	Returns the first note in the available range.
int	getRangeEnd () const noexcept
	Returns the last note in the available range.
void	setLowestVisibleKey (int noteNumber)
	If the keyboard extends beyond the size of the component, this will scroll it to show the given key at the start.
int	getLowestVisibleKey () const noexcept
	Returns the number of the first key shown in the component.
float	getWhiteNoteLength () const noexcept
	Returns the absolute length of the white notes.
void	setBlackNoteLengthProportion (float ratio) noexcept
	Sets the length of the black notes as a proportion of the white note length.
float	getBlackNoteLengthProportion () const noexcept
	Returns the length of the black notes as a proportion of the white note length.
float	getBlackNoteLength () const noexcept
	Returns the absolute length of the black notes.
void	setBlackNoteWidthProportion (float ratio) noexcept
	Sets the width of the black notes as a proportion of the white note width.
float	getBlackNoteWidthProportion () const noexcept
	Returns the width of the black notes as a proportion of the white note width.
float	getBlackNoteWidth () const noexcept
	Returns the absolute width of the black notes.
void	setScrollButtonsVisible (bool canScroll)
	If set to true, then scroll buttons will appear at either end of the keyboard if there are too many notes to fit them all in the component at once.
float	getKeyStartPosition (int midiNoteNumber) const
	Returns the position within the component of the left-hand edge of a key.
float	getTotalKeyboardWidth () const noexcept
	Returns the total width needed to fit all the keys in the available range.
NoteAndVelocity	getNoteAndVelocityAtPosition (Point< float > position, bool includeChildComponents=false)
	Returns the note number and velocity for a given position within the component.
Rectangle< float >	getRectangleForKey (int midiNoteNumber) const
	Returns the rectangle for a given key.
void	setOctaveForMiddleC (int octaveNumForMiddleC)
	This sets the octave number which is shown as the octave number for middle C.
int	getOctaveForMiddleC () const noexcept
	This returns the value set by setOctaveForMiddleC().
virtual void	drawKeyboardBackground (Graphics &g, Rectangle< float > area)=0
	Use this method to draw the background of the keyboard that will be drawn under the white and black notes.
virtual void	drawWhiteKey (int midiNoteNumber, Graphics &g, Rectangle< float > area)=0
	Use this method to draw a white key of the keyboard in a given rectangle.
virtual void	drawBlackKey (int midiNoteNumber, Graphics &g, Rectangle< float > area)=0
	Use this method to draw a black key of the keyboard in a given rectangle.
virtual void	drawUpDownButton (Graphics &g, int w, int h, bool isMouseOver, bool isButtonPressed, bool movesOctavesUp)
	This can be overridden to draw the up and down buttons that scroll the keyboard up/down in octaves.
virtual Range< float >	getKeyPosition (int midiNoteNumber, float keyWidth) const
	Calculates the position of a given midi-note.
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.
void	mouseWheelMove (const MouseEvent &, const MouseWheelDetails &) override
	Called when the mouse-wheel is moved.
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	parentHierarchyChanged ()
	Called to indicate that the component's parents have changed.
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.
virtual WindowControlKind	findControlAtPoint (Point< float >) const
	For components that are added to the desktop, this may be called to determine what kind of control is at particular locations in the window.
virtual void	windowControlClickedClose ()
	For components that are added to the desktop, this may be called to indicate that the mouse was clicked inside the area of the "close" control.
virtual void	windowControlClickedMinimise ()
	For components that are added to the desktop, this may be called to indicate that the mouse was clicked inside the area of the "minimise" control.
virtual void	windowControlClickedMaximise ()
	For components that are added to the desktop, this may be called to indicate that the mouse was clicked inside the area of the "maximise" control.
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.
FontOptions	withDefaultMetrics (FontOptions opt) const
	Returns a copy of the FontOptions with the default metrics kind from the component's LookAndFeel.
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.
virtual void	enablementChanged ()
	Callback to indicate that this component has been enabled or disabled.
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	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 bool	keyPressed (const KeyPress &key)
	Called when a key is pressed.
virtual bool	keyStateChanged (bool isKeyDown)
	Called when a key is pressed or released.
virtual void	modifierKeysChanged (const ModifierKeys &modifiers)
	Called when a modifier key is pressed or released.
virtual void	focusGained (FocusChangeType cause)
	Called to indicate that this component has just acquired the keyboard focus.
virtual void	focusGainedWithDirection (FocusChangeType cause, FocusChangeDirection direction)
	Called to indicate that this component has just acquired the keyboard focus.
virtual void	focusLost (FocusChangeType cause)
	Called to indicate that this component has just lost 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.
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.
virtual std::unique_ptr< AccessibilityHandler >	createAccessibilityHandler ()
	Override this method to return a custom AccessibilityHandler for this component.
Public Member Functions inherited from MouseListener
virtual	~MouseListener ()=default
	Destructor.
Public Member Functions inherited from ChangeBroadcaster
	ChangeBroadcaster () noexcept
	Creates an ChangeBroadcaster.
virtual	~ChangeBroadcaster ()
	Destructor.
void	addChangeListener (ChangeListener *listener)
	Registers a listener to receive change callbacks from this broadcaster.
void	removeChangeListener (ChangeListener *listener)
	Unregisters a listener from the list.
void	removeAllChangeListeners ()
	Removes all listeners from the list.
void	sendChangeMessage ()
	Causes an asynchronous change message to be sent to all the registered listeners.
void	sendSynchronousChangeMessage ()
	Sends a synchronous change message to all the registered listeners.
void	dispatchPendingMessages ()
	If a change message has been sent but not yet dispatched, this will call sendSynchronousChangeMessage() to make the callback immediately.

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 drawing a custom MIDI keyboard component.

Implement the drawKeyboardBackground(), drawWhiteKey(), and drawBlackKey() methods to draw your content and this class will handle the underlying keyboard logic.

The component is a ChangeBroadcaster, so if you want to be informed when the keyboard is scrolled, you can register a ChangeListener for callbacks.

Member Enumeration Documentation

Orientation

enum KeyboardComponentBase::Orientation

The direction of the keyboard.

See also

setOrientation

Enumerator
horizontalKeyboard
verticalKeyboardFacingLeft
verticalKeyboardFacingRight

ColourIds

enum KeyboardComponentBase::ColourIds

Colour IDs to use to change the colour of the octave scroll buttons.

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

See also

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

Enumerator
upDownButtonBackgroundColourId
upDownButtonArrowColourId

Constructor & Destructor Documentation

KeyboardComponentBase()

KeyboardComponentBase::KeyboardComponentBase ( Orientation orientation )

explicit

Constructor.

Parameters

orientation

whether the keyboard is horizontal or vertical

~KeyboardComponentBase()

KeyboardComponentBase::~KeyboardComponentBase ( )

overridedefault

Destructor.

Member Function Documentation

setKeyWidth()

void KeyboardComponentBase::setKeyWidth

(

float

widthInPixels

)

Changes the width used to draw the white keys.

getKeyWidth()

float KeyboardComponentBase::getKeyWidth ( ) const

noexcept

Returns the width that was set by setKeyWidth().

setScrollButtonWidth()

void KeyboardComponentBase::setScrollButtonWidth

(

int

widthInPixels

)

Changes the width used to draw the buttons that scroll the keyboard up/down in octaves.

getScrollButtonWidth()

int KeyboardComponentBase::getScrollButtonWidth ( ) const

noexcept

Returns the width that was set by setScrollButtonWidth().

setOrientation()

void KeyboardComponentBase::setOrientation

(

Orientation

newOrientation

)

Changes the keyboard's current direction.

getOrientation()

Orientation KeyboardComponentBase::getOrientation ( ) const

noexcept

Returns the keyboard's current direction.

isHorizontal()

bool KeyboardComponentBase::isHorizontal ( ) const

noexcept

Returns true if the keyboard's orientation is horizontal.

setAvailableRange()

void KeyboardComponentBase::setAvailableRange	(	int	lowestNote,
		int	highestNote )

Sets the range of midi notes that the keyboard will be limited to.

By default the range is 0 to 127 (inclusive), but you can limit this if you only want a restricted set of the keys to be shown.

Note that the values here are inclusive and must be between 0 and 127.

getRangeStart()

int KeyboardComponentBase::getRangeStart ( ) const

noexcept

Returns the first note in the available range.

See also

setAvailableRange

getRangeEnd()

int KeyboardComponentBase::getRangeEnd ( ) const

noexcept

Returns the last note in the available range.

See also

setAvailableRange

setLowestVisibleKey()

void KeyboardComponentBase::setLowestVisibleKey

(

int

noteNumber

)

If the keyboard extends beyond the size of the component, this will scroll it to show the given key at the start.

Whenever the keyboard's position is changed, this will use the ChangeBroadcaster base class to send a callback to any ChangeListeners that have been registered.

getLowestVisibleKey()

int KeyboardComponentBase::getLowestVisibleKey ( ) const

noexcept

Returns the number of the first key shown in the component.

See also

setLowestVisibleKey

getWhiteNoteLength()

float KeyboardComponentBase::getWhiteNoteLength ( ) const

noexcept

Returns the absolute length of the white notes.

This will be their vertical or horizontal length, depending on the keyboard's orientation.

setBlackNoteLengthProportion()

void KeyboardComponentBase::setBlackNoteLengthProportion ( float ratio )

noexcept

Sets the length of the black notes as a proportion of the white note length.

getBlackNoteLengthProportion()

float KeyboardComponentBase::getBlackNoteLengthProportion ( ) const

noexcept

Returns the length of the black notes as a proportion of the white note length.

getBlackNoteLength()

float KeyboardComponentBase::getBlackNoteLength ( ) const

noexcept

Returns the absolute length of the black notes.

This will be their vertical or horizontal length, depending on the keyboard's orientation.

setBlackNoteWidthProportion()

void KeyboardComponentBase::setBlackNoteWidthProportion ( float ratio )

noexcept

Sets the width of the black notes as a proportion of the white note width.

getBlackNoteWidthProportion()

float KeyboardComponentBase::getBlackNoteWidthProportion ( ) const

noexcept

Returns the width of the black notes as a proportion of the white note width.

getBlackNoteWidth()

float KeyboardComponentBase::getBlackNoteWidth ( ) const

noexcept

Returns the absolute width of the black notes.

This will be their vertical or horizontal width, depending on the keyboard's orientation.

setScrollButtonsVisible()

void KeyboardComponentBase::setScrollButtonsVisible

(

bool

canScroll

)

If set to true, then scroll buttons will appear at either end of the keyboard if there are too many notes to fit them all in the component at once.

getKeyStartPosition()

float KeyboardComponentBase::getKeyStartPosition

(

int

midiNoteNumber

)

const

Returns the position within the component of the left-hand edge of a key.

Depending on the keyboard's orientation, this may be a horizontal or vertical distance, in either direction.

getTotalKeyboardWidth()

float KeyboardComponentBase::getTotalKeyboardWidth ( ) const

noexcept

Returns the total width needed to fit all the keys in the available range.

getNoteAndVelocityAtPosition()

NoteAndVelocity KeyboardComponentBase::getNoteAndVelocityAtPosition	(	Point< float >	position,
		bool	includeChildComponents = false )

Returns the note number and velocity for a given position within the component.

If includeChildComponents is true then this will return a key obscured by any child components.

getRectangleForKey()

Rectangle< float > KeyboardComponentBase::getRectangleForKey

(

int

midiNoteNumber

)

const

Returns the rectangle for a given key.

setOctaveForMiddleC()

void KeyboardComponentBase::setOctaveForMiddleC

(

int

octaveNumForMiddleC

)

This sets the octave number which is shown as the octave number for middle C.

This affects only the default implementation of getWhiteNoteText(), which passes this octave number to MidiMessage::getMidiNoteName() in order to get the note text. See MidiMessage::getMidiNoteName() for more info about the parameter.

By default this value is set to 3.

See also

getOctaveForMiddleC

getOctaveForMiddleC()

int KeyboardComponentBase::getOctaveForMiddleC ( ) const

noexcept

This returns the value set by setOctaveForMiddleC().

See also

setOctaveForMiddleC

drawKeyboardBackground()

virtual void KeyboardComponentBase::drawKeyboardBackground ( Graphics & g, Rectangle< float > area )

pure virtual

Use this method to draw the background of the keyboard that will be drawn under the white and black notes.

This can also be used to draw any shadow or outline effects.

drawWhiteKey()

virtual void KeyboardComponentBase::drawWhiteKey ( int midiNoteNumber, Graphics & g, Rectangle< float > area )

pure virtual

Use this method to draw a white key of the keyboard in a given rectangle.

When doing this, be sure to note the keyboard's orientation.

drawBlackKey()

virtual void KeyboardComponentBase::drawBlackKey ( int midiNoteNumber, Graphics & g, Rectangle< float > area )

pure virtual

Use this method to draw a black key of the keyboard in a given rectangle.

When doing this, be sure to note the keyboard's orientation.

drawUpDownButton()

virtual void KeyboardComponentBase::drawUpDownButton ( Graphics & g, int w, int h, bool isMouseOver, bool isButtonPressed, bool movesOctavesUp )

virtual

This can be overridden to draw the up and down buttons that scroll the keyboard up/down in octaves.

getKeyPosition()

virtual Range< float > KeyboardComponentBase::getKeyPosition ( int midiNoteNumber, float keyWidth ) const

virtual

Calculates the position of a given midi-note.

This can be overridden to create layouts with custom key-widths.

Parameters

midiNoteNumber	the note to find
keyWidth	the desired width in pixels of one key - see setKeyWidth()

Returns

the start and length of the key along the axis of the keyboard

paint()

void KeyboardComponentBase::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 KeyboardComponentBase::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.

mouseWheelMove()

void KeyboardComponentBase::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. (Bear in mind that if you attach a component as a mouse-listener to other components, then those wheel moves will also end up calling this method and being passed up to the parents, which may not be what you intended to happen).

Parameters

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

Reimplemented from Component.

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

• juce_KeyboardComponentBase.h