tgui::CanvasSDL Class Reference

CanvasSDL provides a way to directly render SDL contents on a widget. More...

#include <TGUI/Backend/Renderer/SDL_Renderer/CanvasSDL.hpp>

Inheritance diagram for tgui::CanvasSDL:

Public Types
using	Ptr = std::shared_ptr<CanvasSDL>
	Shared widget pointer.
using	ConstPtr = std::shared_ptr<const CanvasSDL>
	Shared constant widget pointer.
Public Types inherited from tgui::CanvasBase
using	Ptr = std::shared_ptr<CanvasBase>
	Shared widget pointer.
using	ConstPtr = std::shared_ptr<const CanvasBase>
	Shared constant widget pointer.
Public Types inherited from tgui::ClickableWidget
using	Ptr = std::shared_ptr<ClickableWidget>
	Shared widget pointer.
using	ConstPtr = std::shared_ptr<const ClickableWidget>
	Shared constant widget pointer.
Public Types inherited from tgui::Widget
using	Ptr = std::shared_ptr<Widget>
	Shared widget pointer.
using	ConstPtr = std::shared_ptr<const Widget>
	Shared constant widget pointer.

Public Member Functions
	CanvasSDL (const char *typeName=StaticWidgetType, bool initRenderer=true)
	CanvasSDL (const CanvasSDL &copy)
	Copy constructor.
	CanvasSDL (CanvasSDL &&copy)=default
	Default move constructor.
CanvasSDL &	operator= (const CanvasSDL &right)
	Overload of copy assignment operator.
CanvasSDL &	operator= (CanvasSDL &&right)=default
	Default move assignment operator.
void	setSize (const Layout2d &size) override
	Changes the size of the widget.
void	draw (BackendRenderTarget &target, RenderStates states) const override
	Draw the widget to a render target.
SDL_Texture *	getTextureTarget ()
	Access the internal texture on which you can render.
void	setSize (Layout width, Layout height)
	Changes the size of the widget.
Public Member Functions inherited from tgui::CanvasBase
	CanvasBase (const char *typeName, bool initRenderer)
void	ignoreMouseEvents (bool ignore=true)
	Sets whether the widget should completely ignore mouse events and let them pass to the widgets behind it.
bool	isIgnoringMouseEvents () const
	Returns whether the widget is ignoring mouse events and letting them pass to the widgets behind it.
bool	canGainFocus () const override
	Returns whether the widget can gain focus.
bool	isMouseOnWidget (Vector2f pos) const override
	Returns whether the mouse position (which is relative to the parent widget) lies on top of the widget.
Public Member Functions inherited from tgui::ClickableWidget
	ClickableWidget (const char *typeName=StaticWidgetType, bool initRenderer=true)
bool	isMouseOnWidget (Vector2f pos) const override
	Returns whether the mouse position (which is relative to the parent widget) lies on top of the widget.
bool	leftMousePressed (Vector2f pos) override
	Called by the parent when the left mouse button goes down on top of the widget.
void	leftMouseReleased (Vector2f pos) override
void	rightMousePressed (Vector2f pos) override
void	rightMouseReleased (Vector2f pos) override
void	rightMouseButtonNoLongerDown () override
void	draw (BackendRenderTarget &target, RenderStates states) const override
	Draw the widget to a render target.
Public Member Functions inherited from tgui::Widget
	Widget (const char *typeName, bool initRenderer)
	Widget (const Widget &)
	Copy constructor.
	Widget (Widget &&) noexcept
	Move constructor.
virtual	~Widget ()
	Destructor.
Widget &	operator= (const Widget &)
	Overload of copy assignment operator.
Widget &	operator= (Widget &&) noexcept
	Move assignment.
void	setRenderer (std::shared_ptr< RendererData > rendererData)
	Sets a new renderer for the widget. The renderer determines how the widget looks.
virtual WidgetRenderer *	getSharedRenderer ()
	Returns the renderer, which gives access to functions that determine how the widget is displayed.
virtual const WidgetRenderer *	getSharedRenderer () const
virtual WidgetRenderer *	getRenderer ()
	Returns the renderer, which gives access to functions that determine how the widget is displayed.
virtual void	setPosition (const Layout2d &position)
	sets the position of the widget
void	setPosition (Layout x, Layout y)
	Sets the position of the widget.
Vector2f	getPosition () const
	Gets the position of the widget.
void	setSize (Layout width, Layout height)
	Changes the size of the widget.
void	setWidth (Layout width)
	Changes the width of the widget.
void	setHeight (Layout height)
	Changes the height of the widget.
Vector2f	getSize () const
	Returns the size of the widget.
virtual Vector2f	getFullSize () const
	Returns the entire size that the widget is using.
virtual Vector2f	getAbsolutePosition (Vector2f offset={}) const
	Get the absolute position of the widget instead of the relative position to its parent.
virtual Vector2f	getWidgetOffset () const
	Returns the distance between the position where the widget is drawn and where the widget is placed.
void	setAutoLayout (AutoLayout layout)
	Sets how the position is determined compared to the other widgets in the parent.
AutoLayout	getAutoLayout () const
	Returns how the position is determined compared to the other widgets in the parent.
void	setOrigin (float x, float y)
	Sets the origin point on which the position, scale and rotation is based.
void	setOrigin (Vector2f origin)
	Sets the origin point on which the position, scale and rotation is based.
Vector2f	getOrigin () const
	Returns the relative origin point on which the position, scale and rotation is based.
void	setScale (Vector2f scaleFactors)
	Sets the scaling to be applied to the widget.
void	setScale (Vector2f scaleFactors, Vector2f origin)
	Sets the scaling to be applied to the widget.
void	setScale (float scaleFactor)
	Sets the scaling to be applied to the widget.
void	setScale (float scaleFactor, Vector2f origin)
	Sets the scaling to be applied to the widget.
Vector2f	getScale () const
	Returns the scaling to be applied to the widget.
Vector2f	getScaleOrigin () const
	Returns the origin used for scaling.
void	setRotation (float angle)
	Sets the rotation to be applied to the widget.
void	setRotation (float angle, Vector2f origin)
	Sets the rotation to be applied to the widget.
float	getRotation () const
	Returns the rotation to be applied to the widget.
Vector2f	getRotationOrigin () const
	Returns the origin used for rotations.
void	showWithEffect (ShowEffectType type, Duration duration)
	Shows the widget by introducing it with an animation.
void	hideWithEffect (ShowEffectType type, Duration duration)
	Hides the widget by making it leave with an animation.
void	moveWithAnimation (Layout2d position, Duration duration)
	Moves the widget from its current position to the given position, over a given duration.
void	resizeWithAnimation (Layout2d size, Duration duration)
	Resizes the widget from its current size to the given size, over a given duration.
virtual void	setVisible (bool visible)
	Shows or hides a widget.
bool	isVisible () const
	Returns true when the widget is visible.
virtual void	setEnabled (bool enabled)
	Enables or disables the widget.
bool	isEnabled () const
	Returns true when the widget is enabled.
virtual void	setFocused (bool focused)
	Focus or unfocus the widget.
bool	isFocused () const
	Returns true when the widget is focused and false otherwise.
const String &	getWidgetType () const
	Returns the type of the widget.
Container *	getParent () const
	Returns a pointer to the parent widget.
BackendGui *	getParentGui () const
	Returns a pointer to the gui to which this widget belongs.
bool	isAnimationPlaying () const
	Returns whether there is an active animation (started with showWithEffect or hideWithEffect)
void	moveToFront ()
	Places the widget before all other widgets.
void	moveToBack ()
	Places the widget behind all other widgets.
void	setUserData (Any userData)
	Stores some data into the widget.
template<typename DataType >
DataType	getUserData () const
	Returns data stored in the widget.
bool	hasUserData () const
	Returns whether data stored in the widget.
void	setInheritedFont (const Font &font)
	Sets the font of the widget that is used when no font is set in the renderer.
const Font &	getInheritedFont () const
	Returns the font of the widget that is used when no font is set in the renderer.
void	setInheritedOpacity (float opacity)
	Sets the opacity of the widget that will be multiplied with the opacity set in the renderer.
float	getInheritedOpacity () const
	Returns the opacity of the widget that is multiplied with the opacity set in the renderer.
void	setTextSize (unsigned int size)
	Changes the character size of text in this widget if it uses text.
unsigned int	getTextSize () const
	Returns the character size of text in this widget.
void	setToolTip (Widget::Ptr toolTip)
	Sets the tool tip that should be displayed when hovering over the widget.
Widget::Ptr	getToolTip () const
	Returns the tool tip that is displayed when hovering over the widget.
void	setWidgetName (const String &name)
	Changes the name of a widget.
String	getWidgetName () const
	Returns the name of a widget.
void	setMouseCursor (Cursor::Type cursor)
	Changes which mouse cursor is shown when hovering over the widget.
Cursor::Type	getMouseCursor () const
	Returns which mouse cursor is shown when hovering over the widget.
void	setFocusable (bool focusable)
	Changes whether a widget could be focused.
bool	isFocusable () const
	Returns whether a widget could be focused.
void	setNavigationUp (const Widget::Ptr &widgetAbove)
	Changes which widget should become focused when navigating upwards from this widget.
Widget::Ptr	getNavigationUp () const
	Returns which widget would become focused when navigating upwards from this widget.
void	setNavigationDown (const Widget::Ptr &widgetBelow)
	Changes which widget should become focused when navigating downwards from this widget.
Widget::Ptr	getNavigationDown () const
	Returns which widget would become focused when navigating downwards from this widget.
void	setNavigationLeft (const Widget::Ptr &widgetLeft)
	Changes which widget should become focused when navigating to the left from this widget.
Widget::Ptr	getNavigationLeft () const
	Returns which widget would become focused when navigating to the left from this widget.
void	setNavigationRight (const Widget::Ptr &widgetRight)
	Changes which widget should become focused when navigating to the right from this widget.
Widget::Ptr	getNavigationRight () const
	Returns which widget would become focused when navigating to the right from this widget.
void	setIgnoreMouseEvents (bool ignore)
	Sets whether the widget should completely ignore mouse events and let them pass to the widgets behind it.
bool	getIgnoreMouseEvents () const
	Returns whether the widget is ignoring mouse events and letting them pass to the widgets behind it.
void	finishAllAnimations ()
	Makes all animations of the widget finish immediately.
bool	isContainer () const
	Returns whether the widget is a container widget or not.
bool	isMouseDown () const
	Returns whether the left mouse button has been pressed on top of the widget.
virtual void	setParent (Container *parent)
virtual bool	updateTime (Duration elapsedTime)
void	setAutoLayoutUpdateEnabled (bool enabled)
virtual void	mouseReleased (Event::MouseButton button, Vector2f pos)
virtual void	mouseMoved (Vector2f pos)
virtual void	keyPressed (const Event::KeyEvent &event)
virtual bool	canHandleKeyPress (const Event::KeyEvent &event)
	Called by the parent of the widget to check if keyPressed would process the event.
virtual void	textEntered (char32_t key)
virtual bool	scrolled (float delta, Vector2f pos, bool touch)
	Called by the parent on scroll event (either from mouse wheel of from two finger scrolling on a touchscreen)
virtual void	mouseNoLongerOnWidget ()
virtual void	leftMouseButtonNoLongerDown ()
virtual Widget::Ptr	askToolTip (Vector2f mousePos)
const Layout2d &	getPositionLayout () const
const Layout2d &	getSizeLayout () const
void	bindPositionLayout (Layout *layout)
void	unbindPositionLayout (Layout *layout)
void	bindSizeLayout (Layout *layout)
void	unbindSizeLayout (Layout *layout)
template<typename WidgetType >
std::shared_ptr< const WidgetType >	cast () const
	Downcast const widget.
template<typename WidgetType >
std::shared_ptr< WidgetType >	cast ()
	Downcast widget.
void	rendererChangedCallback (const String &property)
virtual void	updateTextSize ()

Static Public Member Functions
static CanvasSDL::Ptr	create (const Layout2d &size={"100%", "100%"})
	Creates a new canvas widget.
static CanvasSDL::Ptr	copy (const CanvasSDL::ConstPtr &canvas)
	Makes a copy of another canvas.
Static Public Member Functions inherited from tgui::ClickableWidget
static ClickableWidget::Ptr	create (const Layout2d &size={"100%", "100%"})
	Creates a new clickable widget.
static ClickableWidget::Ptr	copy (const ClickableWidget::ConstPtr &widget)
	Makes a copy of another clickable widget.

Static Public Attributes
static constexpr const char	StaticWidgetType [] = "CanvasSDL"
	Type name of the widget.
Static Public Attributes inherited from tgui::ClickableWidget
static constexpr const char	StaticWidgetType [] = "ClickableWidget"
	Type name of the widget.

Protected Member Functions
Widget::Ptr	clone () const override
	Makes a copy of the widget if you don't know its exact type.
Protected Member Functions inherited from tgui::CanvasBase
std::unique_ptr< DataIO::Node >	save (SavingRenderersMap &renderers) const override
	Saves the widget as a tree node in order to save it to a file.
void	load (const std::unique_ptr< DataIO::Node > &node, const LoadingRenderersMap &renderers) override
	Loads the widget from a tree of nodes.
Protected Member Functions inherited from tgui::ClickableWidget
Signal &	getSignal (String signalName) override
	Retrieves a signal based on its name.
Widget::Ptr	clone () const override
	Makes a copy of the widget if you don't know its exact type.
Protected Member Functions inherited from tgui::Widget
virtual void	rendererChanged (const String &property)
	Function called when one of the properties of the renderer is changed.
virtual void	mouseEnteredWidget ()
	This function is called when the mouse enters the widget.
virtual void	mouseLeftWidget ()
	This function is called when the mouse leaves the widget.
void	recalculateBoundPositionLayouts ()
	Calls recalculateValue() on each layout in m_boundPositionLayouts.
void	recalculateBoundSizeLayouts ()
	Calls recalculateValue() on each layout in m_boundSizeLayouts.

Protected Attributes
SDL_Texture *	m_textureTarget = nullptr
Vector2u	m_textureSize
Vector2u	m_usedTextureSize
std::shared_ptr< BackendTextureSDL >	m_backendTexture
Protected Attributes inherited from tgui::Widget
String	m_type
String	m_name
Layout2d	m_position
	Stores the position of this widget.
Layout2d	m_size
	Stores the size of this widget.
unsigned int	m_textSize = 0
Vector2f	m_origin
Optional< Vector2f >	m_rotationOrigin
Optional< Vector2f >	m_scaleOrigin
Vector2f	m_scaleFactors = {1, 1}
float	m_rotationDeg = 0
Vector2f	m_prevPosition
Vector2f	m_prevSize
std::unordered_set< Layout * >	m_boundPositionLayouts
std::unordered_set< Layout * >	m_boundSizeLayouts
bool	m_enabled = true
	Stores the flag indicating whether this widget is enabled.
bool	m_visible = true
	Stores the flag indicating whether this widget is visible.
Container *	m_parent = nullptr
BackendGui *	m_parentGui = nullptr
bool	m_mouseHover = false
bool	m_mouseDown = false
bool	m_focused = false
bool	m_focusable = true
std::weak_ptr< Widget >	m_navWidgetUp
std::weak_ptr< Widget >	m_navWidgetDown
std::weak_ptr< Widget >	m_navWidgetRight
std::weak_ptr< Widget >	m_navWidgetLeft
Duration	m_animationTimeElapsed
bool	m_containerWidget = false
Widget::Ptr	m_toolTip = nullptr
aurora::CopiedPtr< WidgetRenderer >	m_renderer = nullptr
std::vector< std::unique_ptr< priv::Animation > >	m_showAnimations
Font	m_inheritedFont
float	m_inheritedOpacity = 1
Any	m_userData
Cursor::Type	m_mouseCursor = Cursor::Type::Arrow
AutoLayout	m_autoLayout = AutoLayout::Manual
bool	m_autoLayoutUpdateEnabled = true
bool	m_ignoreMouseEvents = false
Font	m_fontCached = Font::getGlobalFont()
float	m_opacityCached = 1
bool	m_transparentTextureCached = false
unsigned int	m_textSizeCached = 0

Additional Inherited Members
Public Attributes inherited from tgui::ClickableWidget
SignalVector2f	onMousePress = {"MousePressed"}
	The mouse went down on the widget. Optional parameter: mouse position relative to widget.
SignalVector2f	onMouseRelease = {"MouseReleased"}
	The mouse was released on top of the widget. Optional parameter: mouse position relative to widget.
SignalVector2f	onClick = {"Clicked"}
	The widget was clicked. Optional parameter: mouse position relative to widget.
SignalVector2f	onRightMousePress = {"RightMousePressed"}
	The right mouse button went down on the widget. Optional parameter: mouse position relative to widget.
SignalVector2f	onRightMouseRelease = {"RightMouseReleased"}
	The right mouse button was released on top of the widget. Optional parameter: mouse position relative to widget.
SignalVector2f	onRightClick = {"RightClicked"}
	The widget was right clicked. Optional parameter: mouse position relative to widget.
Public Attributes inherited from tgui::Widget
SignalVector2f	onPositionChange = {"PositionChanged"}
	The position of the widget changed. Optional parameter: new position.
SignalVector2f	onSizeChange = {"SizeChanged"}
	The size of the widget changed. Optional parameter: new size.
Signal	onFocus = {"Focused"}
	The widget was focused.
Signal	onUnfocus = {"Unfocused"}
	The widget was unfocused.
Signal	onMouseEnter = {"MouseEntered"}
	The mouse entered the widget.
Signal	onMouseLeave = {"MouseLeft"}
	The mouse left the widget.
SignalShowEffect	onShowEffectFinish = {"ShowEffectFinished"}
	A show or hide effect finished. Optional parameters: effect type, new widget visibility or both.
SignalAnimationType	onAnimationFinish = {"AnimationFinished"}
	An animation has finished.
Protected Types inherited from tgui::Widget
using	SavingRenderersMap = std::map<const Widget*, std::pair<std::unique_ptr<DataIO::Node>, String>>
using	LoadingRenderersMap = std::map<String, std::shared_ptr<RendererData>>

Detailed Description

CanvasSDL provides a way to directly render SDL contents on a widget.

When gui.draw() is called, all widgets are drawn at once. If you wish to have custom SDL rendering inbetween TGUI widgets (e.g. draw to the background of a child window) then you need to use a CanvasSDL widget.

The canvas widget is essentially just a wrapper around a render target texture. You draw your SDL contents on top of the canvas instead of on the window. The canvas is then added to the gui between the widgets where you want the rendering to appear.

You can redraw the contents of the canvas at any time, but make sure to always start by calling SDL_SetRenderTarget with the texture of the canvas and end the rendering by calling SDL_SetRenderTarget with a nullptr (or other target).

Example:

SDL_Texture* imgTexture;
 
auto canvas = tgui::CanvasSDL::create({400, 300});
gui.add(canvas);
 
SDL_SetRenderTarget(renderer, canvas->getTextureTarget());  // Let drawing happen on the canvas instead of the window
SDL_RenderClear(renderer);                                  // Clear the contents of the canvas
SDL_RenderCopy(renderer, imgTexture, nullptr, nullptr);     // Draw an image to the canvas
SDL_SetRenderTarget(renderer, nullptr);                     // Let further drawing happen on the window again

Member Function Documentation

clone()

Widget::Ptr tgui::CanvasSDL::clone ( ) const

nodiscardoverrideprotectedvirtual

Makes a copy of the widget if you don't know its exact type.

This function should only be used when you don't know the type of the widget. If you know what kind of widget you are copying, you should use the copy function.

Returns

Copy of the widget

Implements tgui::Widget.

copy()

static CanvasSDL::Ptr tgui::CanvasSDL::copy ( const CanvasSDL::ConstPtr & canvas )

staticnodiscard

Makes a copy of another canvas.

Parameters

canvas

The other canvas

Returns

The new canvas

create()

static CanvasSDL::Ptr tgui::CanvasSDL::create ( const Layout2d & size = {"100%", "100%"} )

staticnodiscard

Creates a new canvas widget.

Parameters

size	Size of the canvas

Returns

The new canvas

draw()

void tgui::CanvasSDL::draw ( BackendRenderTarget & target, RenderStates states ) const

overridevirtual

Draw the widget to a render target.

Parameters

target	Render target to draw to
states	Current render states

Implements tgui::Widget.

getTextureTarget()

SDL_Texture * tgui::CanvasSDL::getTextureTarget ( )

inlinenodiscard

Access the internal texture on which you can render.

Returns

Pointer to the internal texture

The texture has a size that is equal or larger than the size of the canvas widget. The pixel format of the texture is SDL_PIXELFORMAT_RGBA32. The texture was created with SDL_TEXTUREACCESS_TARGET access.

setSize() [1/2]

void tgui::CanvasSDL::setSize ( const Layout2d & size )

overridevirtual

Changes the size of the widget.

Parameters

size	The new size of the widget

Reimplemented from tgui::Widget.

setSize() [2/2]

void tgui::Widget::setSize ( Layout width, Layout height )

inline

Changes the size of the widget.

Parameters

width	Width of the widget
height	Height of the widget

Warning

This setSize overload must never be used from internal TGUI code or by custom widget implementations

---

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

• include/TGUI/Backend/Renderer/SDL_Renderer/CanvasSDL.hpp