PixelDataWidget
touchgfx/widgets/PixelDataWidget.hpp
A widget for displaying a buffer of pixel data. This can also be though of as a dynamic bitmap where the dimensions of the bitmap is the same as the dimensions of the widget and the actual bitmap data can be set and updated dynamically. The size of the buffer must match the number of bytes required for the widget calculated as WIDTH x HEIGHT x BYTES_PER_PIXEL. If the LCD is 16 bit per pixel the buffer must hold 2 bytes for each pixel. If the LCD is 24 bit the buffer must hold 3 bytes for each pixel.
Inherits from: Widget, Drawable
Public Functions
virtual void | draw(const Rect & invalidatedArea) const |
Draw this drawable. | |
uint8_t | getAlpha() const |
Gets the current alpha value of the widget. | |
Bitmap::BitmapFormat | getBitmapFormat() const |
Get the format of the pixel data previously set using setBitmapFormat(). | |
uint8_t * | getPixelData() const |
Get the pixel data memory pointer, previously set with setPixelData(). | |
virtual Rect | getSolidRect() const |
Get (the largest possible) rectangle that is guaranteed to be solid (opaque). | |
virtual void | invalidateContent() const |
Tell the framework that the contents of the Drawable needs to be redrawn. | |
PixelDataWidget() | |
void | setAlpha(uint8_t newAlpha) |
Sets the opacity (alpha value). | |
void | setBitmapFormat(Bitmap::BitmapFormat bitmapFormat) |
Set the format of the pixel data. | |
void | setPixelData(uint8_t *const data) |
Set the pixel data to display. | |
Protected Attributes
uint8_t | alpha |
The Alpha for this widget. | |
uint8_t * | buffer |
The buffer where the pixels are copied from. | |
Bitmap::BitmapFormat | format |
The pixel format for the data. | |
Additional inherited members
Public Functions inherited from Widget
virtual void | getLastChild(int16_t , int16_t , Drawable ** last) |
Since a Widget is only one Drawable, Widget::getLastChild simply yields itself as result, but only if the Widget isVisible and isTouchable. | |
Public Functions inherited from Drawable
void | center() |
Centers the Drawable inside its parent. | |
void | centerX() |
Center the Drawable horizontally inside its parent. | |
void | centerY() |
Center the Drawable vertically inside its parent. | |
virtual void | childGeometryChanged() |
This function can be called on parent nodes to signal that the size or position of one or more of its children has changed. | |
Drawable() | |
Initializes a new instance of the Drawable class. | |
void | drawToDynamicBitmap(BitmapId id) |
Render the Drawable object into a dynamic bitmap. | |
void | expand(int margin =0) |
Expands the Drawable to have the same size as its parent with a given margin around the edge. | |
Rect | getAbsoluteRect() 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_t | getHeight() const |
Gets the height of this Drawable. | |
virtual void | getLastChild(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 Rect | getSolidRectAbsolute() |
Helper function for obtaining the largest solid rect (as implemented by getSolidRect()) expressed in absolute coordinates. | |
virtual void | getVisibleRect(Rect & rect) const |
Function for finding the visible part of this drawable. | |
int16_t | getWidth() const |
Gets the width of this Drawable. | |
int16_t | getX() const |
Gets the x coordinate of this Drawable, relative to its parent. | |
int16_t | getY() const |
Gets the y coordinate of this Drawable, relative to its parent. | |
virtual void | handleClickEvent(const ClickEvent & event) |
Defines the event handler interface for ClickEvents. | |
virtual void | handleDragEvent(const DragEvent & event) |
Defines the event handler interface for DragEvents. | |
virtual void | handleGestureEvent(const GestureEvent & event) |
Defines the event handler interface for GestureEvents. | |
virtual void | handleTickEvent() |
Called periodically by the framework if the Drawable instance has subscribed to timer ticks. | |
virtual void | invalidate() const |
Tell the framework that this entire Drawable needs to be redrawn. | |
virtual void | invalidateRect(Rect & invalidatedArea) const |
Request that a region of this drawable is redrawn. | |
bool | isTouchable() const |
Gets whether this Drawable receives touch events or not. | |
bool | isVisible() const |
Gets whether this Drawable is visible. | |
virtual void | moveRelative(int16_t x, int16_t y) |
Moves the drawable. | |
virtual void | moveTo(int16_t x, int16_t y) |
Moves the drawable. | |
virtual void | setHeight(int16_t height) |
Sets the height of this drawable. | |
void | setPosition(const Drawable & drawable) |
Sets the position of the Drawable to the same as the given Drawable. | |
void | setPosition(int16_t x, int16_t y, int16_t width, int16_t height) |
Sets the size and position of this Drawable, relative to its parent. | |
void | setTouchable(bool touch) |
Controls whether this Drawable receives touch events or not. | |
void | setVisible(bool vis) |
Controls whether this Drawable should be visible. | |
virtual void | setWidth(int16_t width) |
Sets the width of this drawable. | |
void | setWidthHeight(const Bitmap & bitmap) |
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates). | |
void | setWidthHeight(const Drawable & drawable) |
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates). | |
void | setWidthHeight(const Rect & other) |
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates). | |
void | setWidthHeight(int16_t width, int16_t height) |
Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates). | |
virtual void | setX(int16_t x) |
Sets the x coordinate of this Drawable, relative to its parent. | |
void | setXY(const Drawable & drawable) |
Sets the x and y coordinates of this Drawable. | |
void | setXY(int16_t x, int16_t y) |
Sets the x and y coordinates of this Drawable, relative to its parent. | |
virtual void | setY(int16_t y) |
Sets the y coordinate of this Drawable, relative to its parent. | |
virtual void | translateRectToAbsolute(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. | |
Rect | rect |
The coordinates of this Drawable, relative to its parent. | |
bool | touchable |
True if this drawable should receive touch events. | |
bool | visible |
True if this drawable should be drawn. | |
Public Functions Documentation
draw
Draw this drawable.
It is a requirement that the draw implementation does not draw outside the region specified by invalidatedArea.
invalidatedArea | The sub-region of this drawable that needs to be redrawn, expressed in coordinates relative to its parent (e.g. for a complete redraw, invalidatedArea will be (0, 0, width, height). |
Reimplements: touchgfx::Drawable::draw
getAlpha
uint8_t getAlpha | ( | ) | const |
Gets the current alpha value of the widget.
The alpha value is in range 255 (solid) to 0 (invisible).
The current alpha value.
getBitmapFormat
Bitmap::BitmapFormat getBitmapFormat | ( | ) | const |
Get the format of the pixel data previously set using setBitmapFormat().
The bitmap format.
getPixelData
uint8_t * getPixelData | ( | ) | const |
Get the pixel data memory pointer, previously set with setPixelData().
The pixel data.
getSolidRect
virtual Rect getSolidRect | ( | ) | const |
Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
This information is important, as any Drawable underneath the solid area does not need to be drawn.
The solid rectangle part of the Drawable.
Note
The rectangle returned must be relative to upper left corner of the Drawable, meaning that a completely solid widget should return the full size Rect(0, 0, getWidth(), getHeight()). If no area can be guaranteed to be solid, an empty Rect must be returned. Failing to return the correct rectangle may result in errors on the display.
Reimplements: touchgfx::Drawable::getSolidRect
invalidateContent
virtual void invalidateContent | ( | ) | const |
Tell the framework that the contents of the Drawable needs to be redrawn.
If the Drawable is invisible, nothing happens. Subclasses of Drawable are encouraged to implement this function and invalidate as little as possible, i.e. the smallest rectangle covering the visual element(s) drawn by the widget.
Reimplements: touchgfx::Drawable::invalidateContent
PixelDataWidget
setAlpha
void setAlpha | ( | uint8_t | newAlpha | ) | |
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).
newAlpha | The new alpha value. 255=solid, 0=invisible. |
Note
The user code must call invalidate() in order to update the display.
setBitmapFormat
void setBitmapFormat | ( | Bitmap::BitmapFormat | bitmapFormat | ) | |
Set the format of the pixel data.
The supported formats depend on the display type. For example grayscale displays do not support color images.
bitmapFormat | Describes the format to use when reading the pixel data. |
setPixelData
void setPixelData | ( | uint8_t *const | data | ) | |
Set the pixel data to display.
The given pointer must contain WIDTH x HEIGHT x BYTES_PER_PIXEL bytes of addressable image data.
data | Image data. |
Protected Attributes Documentation
alpha
uint8_t alpha
The Alpha for this widget.
buffer
uint8_t * buffer
The buffer where the pixels are copied from.
format
Bitmap::BitmapFormat format
The pixel format for the data.