Button
A button with two images. One image showing the unpressed button and one image showing the pressed state.
Inherits from: AbstractButton, Widget, Drawable
Inherited by: ButtonWithIcon, ButtonWithLabel, RepeatButton, ToggleButton
Public Functions
Button() | |
virtual void | draw(const Rect & invalidatedArea) const |
Draw this drawable. | |
uint8_t | getAlpha() const |
Gets the current alpha value of the widget. | |
Bitmap | getCurrentlyDisplayedBitmap() const |
Gets currently displayed bitmap. | |
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. | |
void | setAlpha(uint8_t newAlpha) |
Sets the opacity (alpha value). | |
virtual void | setBitmaps(const Bitmap & bitmapReleased, const Bitmap & bitmapPressed) |
Sets the two bitmaps used by this button. | |
Protected Attributes
uint8_t | alpha |
The current alpha value. 255=solid, 0=invisible. | |
Bitmap | down |
The image to display when button is pressed. | |
Bitmap | up |
The image to display when button is released (normal state). | |
Additional inherited members
Public Functions inherited from AbstractButton
AbstractButton() | |
Sets this Widget touchable so the user can interact with buttons. | |
virtual void | executeAction() |
Executes the previously set action. | |
virtual bool | getPressedState() const |
Function to determine if the AbstractButton is currently pressed. | |
virtual void | handleClickEvent(const ClickEvent & event) |
Updates the current state of the button. | |
void | setAction(GenericCallback< const AbstractButton & > & callback) |
Associates an action with the button. | |
Protected Attributes inherited from AbstractButton
GenericCallback< const AbstractButton & > * | action |
The callback to be executed when this AbstractButton is clicked. | |
bool | pressed |
Is the button pressed or released? True if pressed. | |
Public Functions inherited from Widget
virtual void | getLastChild(int16_t x, int16_t y, 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 & rect) |
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
Button
Button | ( | ) |
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
Reimplemented by: touchgfx::ButtonWithLabel::draw, touchgfx::ButtonWithIcon::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.
getCurrentlyDisplayedBitmap
Bitmap getCurrentlyDisplayedBitmap | ( | ) | const |
Gets currently displayed bitmap.
This depends on the current state of the button, released (normal) or pressed.
The bitmap currently displayed.
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
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.
setBitmaps
virtual void setBitmaps | ( | const Bitmap & | bitmapReleased , | ||
const Bitmap & | bitmapPressed | ||||
) |
Sets the two bitmaps used by this button.
One bitmap for the released (normal) state and one bitmap for the pressed state. The images are expected to be of the same dimensions, and the Button is resized to the dimensions of the pressed Bitmap.
bitmapReleased | Bitmap to use when button is released. |
bitmapPressed | Bitmap to use when button is pressed. |
Note
It is assumed that the dimensions of the bitmaps are the same. Unexpected (visual) behavior may be observed if the bitmaps are of different sizes. The user code must call invalidate() in order to update the button on the display.
Reimplemented by: touchgfx::ToggleButton::setBitmaps
Protected Attributes Documentation
alpha
uint8_t alpha
The current alpha value. 255=solid, 0=invisible.
down
Bitmap down
The image to display when button is pressed.
up
Bitmap up
The image to display when button is released (normal state).