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CacheableContainer

A CacheableContainer can be seen as a regular Container, i.e. a Drawable that can have child nodes. The z-order of children is determined by the order in which Drawables are added to the container - the Drawable added last will be front-most on the screen.

The important difference is that a CacheableContainer can also render its content to a dynamic bitmap which can then be used as a texture in subsequent drawing operations, either as a simple Image or in a TextureMapper. If the bitmap format of the dynamic bitmap differs from the format of the current LCD, the LCD from drawing the bitmap must be setup using HAL::setAuxiliaryLCD().

See: Container, Bitmap, Image, TextureMapper

Inherits from: Container, Drawable

Public Functions

CacheableContainer()
voidenableCachedMode(bool enable)
Toggle cached mode on and off.
uint8_tgetAlpha() const
Gets the current alpha value of the widget.
BitmapIdgetCacheBitmap() const
Get the dynamic bitmap used by the CacheableContainer.
virtual voidinvalidateRect(Rect & invalidatedArea) const
Request that a subregion of this drawable is redrawn.
boolisChildInvalidated() const
Queries the CacheableContainer whether any child widget has been invalidated.
voidsetAlpha(uint8_t newAlpha)
Sets the opacity (alpha value).
voidsetCacheBitmap(BitmapId bitmapId)
Set the dynamic bitmap into which the container content will be rendered.
boolsetSolidRect(const Rect & rect)
Set the solid area on the dynamic bitmap assigned to the CacheableContainer.
voidupdateCache()
Render the container into the attached dynamic bitmap.
voidupdateCache(const Rect & rect)
Render the container into the attached dynamic bitmap.

Additional inherited members

Public Functions inherited from Container

virtual voidadd(Drawable & d)
Adds a Drawable instance as child to this Container.
Container()
virtual boolcontains(const Drawable & d)
Query if a given Drawable has been added directly to this Container.
virtual voiddraw(const Rect & invalidatedArea) const
Draw this drawable.
virtual voidforEachChild(GenericCallback< Drawable & > * function)
Executes the specified callback function for each child in the Container.
virtual Drawable *getFirstChild()
Obtain a pointer to the first child of this container.
virtual voidgetLastChild(int16_t x, int16_t y, Drawable ** last)
Gets the last child in the list of children in this Container.
virtual RectgetSolidRect() const
Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
virtual voidinsert(Drawable * previous, Drawable & d)
Inserts a Drawable after a specific child node.
virtual voidremove(Drawable & d)
Removes a Drawable from the container by removing it from the linked list of children.
virtual voidremoveAll()
Removes all children in the Container by resetting their parent and sibling pointers.
virtual voidunlink()
Removes all children by unlinking the first child.

Protected Functions inherited from Container

virtual RectgetContainedArea() const
Gets a rectangle describing the total area covered by the children of this container.
virtual voidmoveChildrenRelative(int16_t deltaX, int16_t deltaY)
Calls moveRelative on all children.

Protected Attributes inherited from Container

Drawable *firstChild
Pointer to the first child of this container. Subsequent children can be found through firstChild's nextSibling.

Public Functions inherited from Drawable

virtual voidchildGeometryChanged()
This function can be called on parent nodes to signal that the size or position of one or more of its children has changed.
virtual voiddraw(const Rect & invalidatedArea) const =0
Draw this drawable.
Drawable()
Initializes a new instance of the Drawable class.
voiddrawToDynamicBitmap(BitmapId id)
Render the Drawable object into a dynamic bitmap.
RectgetAbsoluteRect() const
Helper function for obtaining the rectangle this Drawable covers, expressed in absolute coordinates.
virtual Drawable *getFirstChild()
Function for obtaining the first child of this drawable if any.
int16_tgetHeight() const
Gets the height of this Drawable.
virtual voidgetLastChild(int16_t x, int16_t y, Drawable ** last) =0
Function for obtaining the the last child of this drawable that intersects with the specified point.
Drawable *getNextSibling()
Gets the next sibling node.
Drawable *getParent() const
Returns the parent node.
const Rect &getRect() const
Gets the rectangle this Drawable covers, in coordinates relative to its parent.
virtual RectgetSolidRect() const =0
Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
virtual RectgetSolidRectAbsolute()
Helper function for obtaining the largest solid rect (as implemented by getSolidRect()) expressed in absolute coordinates.
virtual voidgetVisibleRect(Rect & rect) const
Function for finding the visible part of this drawable.
int16_tgetWidth() const
Gets the width of this Drawable.
int16_tgetX() const
Gets the x coordinate of this Drawable, relative to its parent.
int16_tgetY() const
Gets the y coordinate of this Drawable, relative to its parent.
virtual voidhandleClickEvent(const ClickEvent & event)
Defines the event handler interface for ClickEvents.
virtual voidhandleDragEvent(const DragEvent & event)
Defines the event handler interface for DragEvents.
virtual voidhandleGestureEvent(const GestureEvent & event)
Defines the event handler interface for GestureEvents.
virtual voidhandleTickEvent()
Called periodically by the framework if the Drawable instance has subscribed to timer ticks.
virtual voidinvalidate() const
Tell the framework that this entire Drawable needs to be redrawn.
boolisTouchable() const
Gets whether this Drawable receives touch events or not.
boolisVisible() const
Gets whether this Drawable is visible.
virtual voidmoveRelative(int16_t x, int16_t y)
Moves the drawable.
virtual voidmoveTo(int16_t x, int16_t y)
Moves the drawable.
virtual voidsetHeight(int16_t height)
Sets the height of this drawable.
voidsetPosition(const Drawable & drawable)
Sets the position of the Drawable to the same as the given Drawable.
voidsetPosition(int16_t x, int16_t y, int16_t width, int16_t height)
Sets the size and position of this Drawable, relative to its parent.
voidsetTouchable(bool touch)
Controls whether this Drawable receives touch events or not.
voidsetVisible(bool vis)
Controls whether this Drawable should be visible.
virtual voidsetWidth(int16_t width)
Sets the width of this drawable.
voidsetWidthHeight(const Bitmap & bitmap)
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
voidsetWidthHeight(const Drawable & drawable)
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
voidsetWidthHeight(const Rect & rect)
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
voidsetWidthHeight(int16_t width, int16_t height)
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
virtual voidsetX(int16_t x)
Sets the x coordinate of this Drawable, relative to its parent.
voidsetXY(const Drawable & drawable)
Sets the x and y coordinates of this Drawable.
voidsetXY(int16_t x, int16_t y)
Sets the x and y coordinates of this Drawable, relative to its parent.
virtual voidsetY(int16_t y)
Sets the y coordinate of this Drawable, relative to its parent.
virtual voidtranslateRectToAbsolute(Rect & r) const
Helper function for converting a region of this Drawable to absolute coordinates.
virtual ~Drawable()
Finalizes an instance of the Drawable class.

Protected Attributes inherited from Drawable

Drawable *nextSibling
Pointer to the next Drawable.
Drawable *parent
Pointer to this drawable's parent.
Rectrect
The coordinates of this Drawable, relative to its parent.
booltouchable
True if this drawable should receive touch events.
boolvisible
True if this drawable should be drawn.

Public Functions Documentation

CacheableContainer

enableCachedMode

void enableCachedMode(boolenable)

Toggle cached mode on and off.

The CacheableContainer behaves just like a regular Container when cached mode is turned off.

Parameters:
enableEnable or disable cached mode.

getAlpha

uint8_t getAlpha()const

Gets the current alpha value of the widget.

The alpha value is in range 255 (solid) to 0 (invisible).

Returns:

The current alpha value.

See also:

getCacheBitmap

BitmapId getCacheBitmap()const

Get the dynamic bitmap used by the CacheableContainer.

Returns:

the id of the assigned bitmap or BITMAP_INVALID if no bitmap has been assigned.

See also:

invalidateRect

virtual void invalidateRect(Rect &invalidatedArea)

Request that a subregion of this drawable is redrawn.

Will recursively traverse the children. When this function returns, the specified invalidated area has been redrawn for all appropriate Drawables covering the region.

Parameters:
invalidatedAreaThe area of this drawable to redraw expressed in coordinates relative to its parent (e.g. to request a complete redraw, invalidatedArea will be (0, 0, width, height).

Reimplements: touchgfx::Drawable::invalidateRect

isChildInvalidated

bool isChildInvalidated()const

Queries the CacheableContainer whether any child widget has been invalidated.

Returns:

True if a child widget has been invalidated and false otherwise.

setAlpha

void setAlpha(uint8_tnewAlpha)

Sets the opacity (alpha value).

This can be used to fade it away by gradually decreasing the alpha value from 255 (solid) to 0 (invisible).

Parameters:
newAlphaThe new alpha value. 255=solid, 0=invisible.
Note

The user code must call invalidate() in order to update the display.The alpha is only applied when cached mode is enabled.

See also:

setCacheBitmap

void setCacheBitmap(BitmapIdbitmapId)

Set the dynamic bitmap into which the container content will be rendered.

The format of the bitmap must be the same as the current LCD or the same as the auxiliary LCD setup using HAL::setAuxiliaryLCD.

Parameters:
bitmapIdId of the dynamic bitmap to serve as a render target.
See also:

setSolidRect

bool setSolidRect(const Rect &rect)

Set the solid area on the dynamic bitmap assigned to the CacheableContainer.

Parameters:
rectThe rectangle of th CacheableContainer that is solid.
Returns:

true if the operation succeeds, false otherwise.

updateCache

void updateCache()

Render the container into the attached dynamic bitmap.

See also:

updateCache

void updateCache(const Rect &rect)

Render the container into the attached dynamic bitmap.

Only the specified Rect region is updated.

Parameters:
rectRegion to update.
See also: