tgui::BackendGuiSDL Class Reference

Inheritance diagram for tgui::BackendGuiSDL:

Public Member Functions
	BackendGuiSDL ()=default
	Default constructor.
bool	handleEvent (const SDL_Event &event)
	Passes the event to the widgets.
void	mainLoop (Color clearColor={240, 240, 240}) override
	Give the gui control over the main loop.
bool	convertEvent (const SDL_Event &eventSDL, Event &eventTGUI)
	Helper function that converts an SDL event to a TGUI event.
SDL_Window *	getWindow () const
	Returns the window that was provided to the gui.
void	startTextInput (FloatRect inputRect) override
	This function is called by TGUI when focusing a text field (EditBox or TextArea). It may result in the software keyboard being opened.
void	stopTextInput () override
	This function is called by TGUI when unfocusing a text field (EditBox or TextArea). It may result in the software keyboard being closed.
void	updateTextCursorPosition (FloatRect inputRect, Vector2f caretPos) override
	This function is called by TGUI when the position of the caret changes in a text field (EditBox or TextArea). If an IME is used then this function may move the IME candidate list to the text cursor position.
bool	isKeyboardModifierPressed (Event::KeyModifier modifierKey) const override
	Checks the state for one of the modifier keys.
bool	handleEvent (Event event)
	Passes the event to the widgets.
Public Member Functions inherited from tgui::BackendGui
	BackendGui ()
	Default constructor.
	BackendGui (const BackendGui &copy)=delete
BackendGui &	operator= (const BackendGui &right)=delete
void	setAbsoluteViewport (const FloatRect &viewport)
	Sets the part of the screen to which the gui will render in pixels.
void	setRelativeViewport (const FloatRect &viewport)
	Sets the part of the screen to which the gui will render as a ratio relative to the window size.
RelFloatRect	getViewport () const
	Returns to which part of the screen the gui will render.
void	setAbsoluteView (const FloatRect &view)
	Sets the part of the gui that will be used to fill the viewport in pixels.
void	setRelativeView (const FloatRect &view)
	Sets the part of the gui that will be used to fill the viewport.
RelFloatRect	getView () const
	Returns the part of the gui that will be used to fill the viewport.
bool	handleEvent (Event event)
	Passes the event to the widgets.
void	setTabKeyUsageEnabled (bool enabled)
	When the tab key usage is enabled, pressing tab will focus another widget.
bool	isTabKeyUsageEnabled () const
	Returns whether the tab key usage is enabled (if so, pressing tab will focus another widget)
virtual void	draw ()
	Draws all the widgets that were added to the gui.
RootContainer::Ptr	getContainer () const
	Returns the internal container of the Gui.
std::shared_ptr< BackendRenderTarget >	getBackendRenderTarget () const
	Returns the backend render target that is assigned to the gui.
void	setFont (const Font &font)
	Changes the global font.
Font	getFont () const
	Returns the global font for this gui.
const std::vector< Widget::Ptr > &	getWidgets () const
	Returns a list of all the widgets.
void	add (const Widget::Ptr &widgetPtr, const String &widgetName="")
	Adds a widget to the container.
Widget::Ptr	get (const String &widgetName) const
	Returns a pointer to an earlier created widget.
template<class WidgetType >
WidgetType::Ptr	get (const String &widgetName) const
	Returns a pointer to an earlier created widget.
bool	remove (const Widget::Ptr &widget)
	Removes a single widget that was added to the container.
void	removeAllWidgets ()
	Removes all widgets that were added to the container.
Widget::Ptr	getFocusedChild () const
	Returns the child widget that is focused inside this container.
Widget::Ptr	getFocusedLeaf () const
	Returns the leaf child widget that is focused inside this container.
Widget::Ptr	getWidgetAtPosition (Vector2f pos) const
	Returns the leaf child widget that is located at the given position.
Widget::Ptr	getWidgetAtPos (Vector2f pos, bool recursive) const
	Returns the widget that is located at the given position.
Widget::Ptr	getWidgetBelowMouseCursor (Vector2i mousePos) const
	Returns the leaf child widget below the mouse.
Widget::Ptr	getWidgetBelowMouseCursor (Vector2i mousePos, bool recursive) const
	Returns the widget below the mouse.
bool	focusNextWidget (bool recursive=true)
	Focuses the next widget in the gui.
bool	focusPreviousWidget (bool recursive=true)
	Focuses the previous widget in the gui.
void	unfocusAllWidgets ()
	Unfocus all the widgets.
void	moveWidgetToFront (const Widget::Ptr &widget)
	Places a widget before all other widgets, to the front of the z-order.
void	moveWidgetToBack (const Widget::Ptr &widget)
	Places a widget behind all other widgets, to the back of the z-order.
std::size_t	moveWidgetForward (const Widget::Ptr &widget)
	Places a widget one step forward in the z-order.
std::size_t	moveWidgetBackward (const Widget::Ptr &widget)
	Places a widget one step backward in the z-order.
bool	setWidgetIndex (const Widget::Ptr &widget, std::size_t index)
	Changes the index of a widget in this container.
int	getWidgetIndex (const Widget::Ptr &widget) const
	Returns the current index of a widget in this container.
void	setOpacity (float opacity)
	Changes the opacity of all widgets.
float	getOpacity () const
	Returns the opacity of all the widgets.
void	setTextSize (unsigned int size)
	Changes the character size of all existing and future child widgets.
unsigned int	getTextSize () const
	Returns the character size for future child widgets (and for existing widgets where the size wasn't changed)
void	loadWidgetsFromFile (const String &filename, bool replaceExisting=true)
	Loads the child widgets from a text file.
void	saveWidgetsToFile (const String &filename)
	Saves the child widgets to a text file.
void	loadWidgetsFromStream (std::stringstream &stream, bool replaceExisting=true)
	Loads the child widgets from a string stream.
void	loadWidgetsFromStream (std::stringstream &&stream, bool replaceExisting=true)
	Loads the child widgets from a string stream.
void	saveWidgetsToStream (std::stringstream &stream) const
	Saves this the child widgets to a text file.
void	setOverrideMouseCursor (Cursor::Type type)
	Overrides which cursor gets shown.
void	restoreOverrideMouseCursor ()
	Undoes the effect of the last call to setOverrideCursor.
void	requestMouseCursor (Cursor::Type type)
	Function that is used by widgets to change the mouse cursor.
void	setDrawingUpdatesTime (bool drawUpdatesTime)
	Sets whether drawing the gui will automatically update the internal clock or whether the user does it manually.
bool	updateTime ()
	Updates the internal clock (for timers, animations and blinking edit cursors)
bool	updateTime (Duration elapsedTime)
Vector2f	mapPixelToCoords (Vector2i pixel) const
	Converts the pixel coordinate to a position within the view.
Vector2f	mapCoordsToPixel (Vector2f coord) const
	Converts a position within the view to the corresponding pixel coordinate.
void	setKeyboardNavigationEnabled (bool enabled)
	Changes whether using the arrow keys can be used to navigate between widgets.
bool	isKeyboardNavigationEnabled () const
	Returns whether using the arrow keys can be used to navigate between widgets.

Protected Member Functions
void	setGuiWindow (SDL_Window *window)
	Sets the window on which the gui should be drawn.
void	updateContainerSize () override
virtual void	presentScreen ()=0
	Shows the drawn content with SDL_GL_SwapWindow or SDL_RenderPresent, depending on the renderer.
Protected Member Functions inherited from tgui::BackendGui
bool	handleTwoFingerScroll (bool wasAlreadyScrolling)
Event::KeyboardKey	translateKeypadKey (Event::KeyboardKey key)

Protected Attributes
SDL_Window *	m_window = nullptr
float	m_dpiScale = 1
bool	m_textInputStarted = false
SDL_Rect	m_textInputRect = {}
bool	m_touchFirstFingerDown = false
SDL_FingerID	m_touchFirstFingerId = 0
SDL_TouchID	m_touchFirstFingerTouchId = 0
Protected Attributes inherited from tgui::BackendGui
std::chrono::steady_clock::time_point	m_lastUpdateTime
bool	m_windowFocused = true
RootContainer::Ptr	m_container = std::make_shared<RootContainer>()
Widget::Ptr	m_visibleToolTip = nullptr
Duration	m_tooltipTime
bool	m_tooltipPossible = false
Vector2f	m_toolTipRelativePos
Vector2i	m_lastMousePos
TwoFingerScrollDetect	m_twoFingerScroll
Vector2i	m_framebufferSize
RelFloatRect	m_viewport {RelativeValue{0}, RelativeValue{0}, RelativeValue{1}, RelativeValue{1}}
RelFloatRect	m_view {RelativeValue{0}, RelativeValue{0}, RelativeValue{1}, RelativeValue{1}}
FloatRect	m_lastView
bool	m_drawUpdatesTime = true
bool	m_tabKeyUsageEnabled = true
bool	m_keyboardNavigationEnabled = false
Cursor::Type	m_requestedMouseCursor = Cursor::Type::Arrow
std::stack< Cursor::Type >	m_overrideMouseCursors
std::shared_ptr< BackendRenderTarget >	m_backendRenderTarget = nullptr

Additional Inherited Members
Public Attributes inherited from tgui::BackendGui
SignalFloatRect	onViewChange = {"ViewChanged"}
	The view was changed. Optional parameter: new view rectangle.
Signal	onWindowFocus = {"WindowFocused"}
	The window sent a GainedFocus event.
Signal	onWindowUnfocus = {"WindowUnfocused"}
	The window sent a LostFocus event.

Constructor & Destructor Documentation

BackendGuiSDL()

tgui::BackendGuiSDL::BackendGuiSDL ( )

default

Default constructor.

Warning

setGuiWindow has to be called by the subclass that inherits from this base class before the gui is used

Member Function Documentation

convertEvent()

bool tgui::BackendGuiSDL::convertEvent ( const SDL_Event & eventSDL, Event & eventTGUI )

nodiscard

Helper function that converts an SDL event to a TGUI event.

Parameters

eventSDL	The input SDL event
eventTGUI	The output TGUI event

Returns

Did the SDL event match on a TGUI event and has the output event been written to?

You typically don't need this function as you can call handleEvent directly with an SDL_Event.

getWindow()

SDL_Window * tgui::BackendGuiSDL::getWindow

(

)

const

Returns the window that was provided to the gui.

Returns

Window that was set via the constructor or setWindow

handleEvent() [1/2]

bool tgui::BackendGuiSDL::handleEvent

(

const SDL_Event &

event

)

Passes the event to the widgets.

Parameters

event

The event that was polled from the window

Returns

Has the event been consumed? When this function returns false, then the event was ignored by all widgets.

You should call this function in your event loop.

SDL_Event event;
while (SDL_PollEvent(&event) != 0) {
    gui.handleEvent(event);
}

handleEvent() [2/2]

bool tgui::BackendGui::handleEvent

(

Event

event

)

Passes the event to the widgets.

Parameters

event

The event that was polled from the window

Returns

Has the event been consumed? When this function returns false, then the event was ignored by all widgets.

isKeyboardModifierPressed()

bool tgui::BackendGuiSDL::isKeyboardModifierPressed ( Event::KeyModifier modifierKey ) const

nodiscardoverridevirtual

Checks the state for one of the modifier keys.

Parameters

modifierKey

The modifier key of which the state is being queried

Returns

Whether queries modifier key is being pressed

Reimplemented from tgui::BackendGui.

mainLoop()

void tgui::BackendGuiSDL::mainLoop ( Color clearColor = {240, 240, 240} )

overridevirtual

Give the gui control over the main loop.

Parameters

clearColor

background color of the window

This function is only intended in cases where your program only needs to respond to gui events. For multimedia applications, games, or other programs where you want a high framerate or do a lot of processing in the main loop, you should use your own main loop.

You can consider this function to execute something similar (but not identical) to the following code:

while (!quit)
{
    SDL_Event event;
    while (SDL_PollEvent(&event) != 0)
    {
        gui.handleEvent(event);
        if (event.type == SDL_EVENT_QUIT)  // SDL_QUIT in SDL2, SDL_EVENT_QUIT in SDL3
            quit = true;
    }
 
    SDL_RenderClear(renderer);  // glClear(GL_COLOR_BUFFER_BIT) when using OpenGL instead of SDL_Renderer
    gui.draw();
    SDL_RenderPresent(renderer);  // SDL_GL_SwapWindow(window) when using OpenGL instead of SDL_Renderer
}

Implements tgui::BackendGui.

presentScreen()

virtual void tgui::BackendGuiSDL::presentScreen ( )

protectedpure virtual

Shows the drawn content with SDL_GL_SwapWindow or SDL_RenderPresent, depending on the renderer.

Implemented in tgui::SDL_GLES2::Gui, tgui::SDL_OPENGL3::Gui, tgui::SDL_RENDERER::Gui, tgui::SDL_TTF_GLES2::Gui, and tgui::SDL_TTF_OPENGL3::Gui.

setGuiWindow()

void tgui::BackendGuiSDL::setGuiWindow ( SDL_Window * window )

protected

Sets the window on which the gui should be drawn.

Parameters

window

The SDL window that will be used by the gui

startTextInput()

void tgui::BackendGuiSDL::startTextInput ( FloatRect inputRect )

overridevirtual

This function is called by TGUI when focusing a text field (EditBox or TextArea). It may result in the software keyboard being opened.

Parameters

inputRect

The rectangle where text is being inputted

Reimplemented from tgui::BackendGui.

stopTextInput()

void tgui::BackendGuiSDL::stopTextInput ( )

overridevirtual

This function is called by TGUI when unfocusing a text field (EditBox or TextArea). It may result in the software keyboard being closed.

Reimplemented from tgui::BackendGui.

updateContainerSize()

void tgui::BackendGuiSDL::updateContainerSize ( )

overrideprotectedvirtual

Reimplemented from tgui::BackendGui.

updateTextCursorPosition()

void tgui::BackendGuiSDL::updateTextCursorPosition ( FloatRect inputRect, Vector2f caretPos )

overridevirtual

This function is called by TGUI when the position of the caret changes in a text field (EditBox or TextArea). If an IME is used then this function may move the IME candidate list to the text cursor position.

Parameters

inputRect	The rectangle where text is being inputted
caretPos	Location of the text cursor, relative to the gui view

Reimplemented from tgui::BackendGui.

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

• include/TGUI/Backend/Window/SDL/BackendGuiSDL.hpp