tachyon::ImageWindowBackend Class Reference

Adds windows that render to an image (WindowFlags::RenderToImage) to another window backend. More...

#include <gui_core/windows/gui_image_window_backend.h>

Inheritance diagram for tachyon::ImageWindowBackend:

Public Member Functions
	ImageWindowBackend (IWindowBackend &osBackend)
	~ImageWindowBackend () override
bool	IsImageWindow (OSWindowHandle window) const
	True when window is one of this backend's image windows.
void	SetPointer (OSWindowHandle window, int2 screenPos, MouseButtons buttons)
	The pointer is over an image window, at this screen position with these buttons held; it is then the window under the mouse.
void	SetFocus (OSWindowHandle window)
	The image window with keyboard focus, reported as the active window.
void	SetGraphicsContext (GraphicsContext *graphicsContext) override
	The graphics context the windows are made for and painted with (during an OS live resize).
OSWindowHandle	CreateWindow (std::string_view title, int2 size, WindowFlags windowFlags, OSWindowHandle parentOSHandle) override
	Creates a window whose client area is size pixels, placed by the OS.
OSWindowHandle	CreateWindow (std::string_view title, IntRect rect, WindowFlags windowFlags, OSWindowHandle parentOSHandle) override
	Creates a window whose client area is rect (screen pixels); otherwise as the size overload.
bool	DestroyWindow (OSWindowHandle window) override
	Queues the window for destruction: the next PollEvents passes its context to cleanup, then destroys it.
void	AttachInputHandlerToWindow (OSWindowHandle window, IPlatformInputHandler *inputHandler) override
	Where the window's input goes (see IPlatformInputHandler); not owned, nullptr for none.
void	AttachContextToWindow (OSWindowHandle window, IWindowContext *context) override
	Stores the window's context (not owned), for GetWindowContext, for the ID passed with the window's input, and for PollEvents' cleanup.
void	DetachWindowContext (OSWindowHandle window) override
	Clears the context pointer stored in the OS window, so PollEvents' cleanup callback gets nullptr instead of double-freeing a context the caller destroys.
bool	IsWindow (OSWindowHandle window) override
	True while the handle is a live window of this backend; false once it was destroyed (by code or the user) and for nullptr.
IWindowContext *	GetWindowContext (OSWindowHandle window) override
	The context attached with AttachContextToWindow, or nullptr.
void	BringToFront (OSWindowHandle window) override
	Raises the window above the others and asks the OS for the input focus.
OSWindowHandle	GetWindowUnderMouse () override
	The backend's window under the mouse, or nullptr.
OSWindowHandle	GetActiveWindow () override
	The window with the keyboard focus, or nullptr when none of the backend's windows has it.
uint32_t	GetFocusChangeCount () const override
	Goes up whenever keyboard focus moves between windows, or to or from another application; open popups are checked against it.
void	PollEvents (std::function< void(OSWindowHandle, IWindowContext *)> cleanup) override
	Handles the OS's pending events, delivering input to the attached handlers.
int2	GetScreenMousePos () override
	The mouse position in screen pixels (SDL: as of the last PollEvents).
std::optional< color4b >	ReadScreenPixel (int2 screenPos) override
	The color of a screen pixel, anywhere on the desktop (an eyedropper); nothing where the platform can't read the screen.
bool	TakeCloseRequest (OSWindowHandle window) override
	Whether the OS asked to close a WindowFlags::ConfirmClose window since last asked.
MouseButtons	GetMouseButtons () override
	The mouse buttons held down, wherever the mouse is (SDL: as of the last PollEvents).
void	SetCursor (MouseCursor cursor) override
	Shows the system cursor for that shape; MouseCursor::None hides the cursor.
void	SetTextInputArea (OSWindowHandle window, IntRect rect) override
	Where text is being typed in the window (window coordinates), so the IME places its candidate list next to it.
float	GetWindowDisplayScale (OSWindowHandle window) override
	The UI scale the OS asks for in this window: pixel density times the monitor's content scale (1.5 on a 150% display).
IntRect	GetWindowPixelRect (OSWindowHandle window) override
	The window's render target: OS position (for OS compositing) and size in physical pixels.
void	SwapBuffers (OSWindowHandle window) override
	Presents for a graphics API that swaps through the window (OpenGL).
IntRect	GetWindowRect (OSWindowHandle window) override
	Client area in pixels; {0,0,0,0} while minimized.
int2	GetWindowPos (OSWindowHandle window) override
	The client area's top-left in screen pixels.
int2	GetWindowSize (OSWindowHandle window) override
	The client area's size in pixels; {0,0} while minimized.
void *	GetNativeHandle (OSWindowHandle window) override
	The OS's own window handle, passed to GraphicsContext::CreateWindowContext (HWND on Windows, NSWindow on macOS, an X11 window or Wayland surface on Linux); nullptr without one.
bool	SetWindowRect (OSWindowHandle window, const IntRect &clientRect) override
	Moves and resizes the window so its client area is clientRect (screen pixels); the backend accounts for the frame.
void	SetWindowVisible (OSWindowHandle window, bool visible) override
	Shows or hides the window; hiding doesn't destroy it.
void	SetWindowMode (OSWindowHandle window, WindowMode mode) override
	Sets the window's state: minimized, maximized, restored or fullscreen.
WindowMode	GetWindowMode (OSWindowHandle window) const override
	The window's state as the OS has it now; WindowMode::Normal by default.
std::vector< MonitorInfo >	GetMonitors () const override
	Every monitor, the primary first.
int	GetMonitorAt (int2 pos) const override
	Index into GetMonitors of the monitor holding the screen point pos; 0 (the primary) when no monitor holds it, -1 without monitors.
int	GetMonitorFromWindow (OSWindowHandle window) const override
	Index into GetMonitors of the window's monitor; -1 for an unknown window.
uint32_t	GetTicks () const override
	A millisecond clock (SDL: since SDL started).
std::string	GetPreferredLanguage () const override
	The user's preferred language as a BCP 47 tag ("ja", "en-US"), or empty when the platform doesn't say.
int32_t	GetCursorSize () const override
	The OS mouse cursor's size in pixels (its accessibility size at the display's scale), or 0 when the platform doesn't say.
Public Member Functions inherited from tachyon::IWindowBackend
	IWindowBackend ()
virtual	~IWindowBackend ()
virtual float	GetDoubleClickMilliseconds ()
	The OS's double-click time in milliseconds, or 0 where the platform has none.
virtual bool	PrefersReducedMotion ()
	Whether the OS asks for less motion (animations turned off); false where the platform has no such setting.
virtual bool	SetWindowCloaked (OSWindowHandle, bool)
	Cloaks a shown window: it takes frames but stays invisible, so it can be drawn before it appears.
virtual uint32_t	ShowFade (OSWindowHandle, IWindowContext *, IntRect, float)
	A layered stand-in for window showing what context drew last, at screenRect (screen pixels) and opacity (0 to 1), so the window itself can be hidden or cloaked while it fades in or out.
virtual void	MoveFade (uint32_t, IntRect, float)
	Moves a stand-in and sets its opacity.
virtual void	EndFade (uint32_t)
	Removes a stand-in.
void	SetWindowMovedCallback (std::function< void()> cb)
	Sets cb, called as soon as any window moves or resizes, even inside the OS modal move / resize loop (before the next frame), so it must be safe outside the frame.
void	SetHitTestCallback (std::function< WindowHitArea(OSWindowHandle, int2 screenPos)> cb)
	Classifies points (screen pixels) of CustomTitleBar windows for the OS.
WindowHitArea	HitTestWindow (OSWindowHandle window, int2 screenPos) const
	What a point (screen pixels) of the window is, from the hit-test callback; WindowHitArea::Client without one.

Additional Inherited Members
Protected Attributes inherited from tachyon::IWindowBackend
std::function< void()>	m_onWindowMoved
	Set by SetWindowMovedCallback; a backend calls it when a window moves or resizes.
std::function< WindowHitArea(OSWindowHandle, int2)>	m_hitTest
	Set by SetHitTestCallback; a backend asks it through HitTestWindow.
GraphicsContext *	m_graphicsContext = nullptr
	Set by SetGraphicsContext; not owned.

Detailed Description

Adds windows that render to an image (WindowFlags::RenderToImage) to another window backend.

They have no OS window: the backend keeps their rect and attached context, and everything else goes to the wrapped backend. The host feeds their input; SetPointer and SetFocus say where it goes.

Constructor & Destructor Documentation

ImageWindowBackend()

tachyon::ImageWindowBackend::ImageWindowBackend ( IWindowBackend & osBackend )

explicit

~ImageWindowBackend()

tachyon::ImageWindowBackend::~ImageWindowBackend ( )

override

Member Function Documentation

IsImageWindow()

bool tachyon::ImageWindowBackend::IsImageWindow

(

OSWindowHandle

window

)

const

True when window is one of this backend's image windows.

SetPointer()

void tachyon::ImageWindowBackend::SetPointer	(	OSWindowHandle	window,
		int2	screenPos,
		MouseButtons	buttons )

The pointer is over an image window, at this screen position with these buttons held; it is then the window under the mouse.

Null window: the pointer is back on the OS windows.

SetFocus()

void tachyon::ImageWindowBackend::SetFocus

(

OSWindowHandle

window

)

The image window with keyboard focus, reported as the active window.

Null: the OS decides again.

SetGraphicsContext()

void tachyon::ImageWindowBackend::SetGraphicsContext ( GraphicsContext * graphicsContext )

inlineoverridevirtual

The graphics context the windows are made for and painted with (during an OS live resize).

GUIApplication::Initialize sets it before initializing the context.

Reimplemented from tachyon::IWindowBackend.

CreateWindow() [1/2]

OSWindowHandle tachyon::ImageWindowBackend::CreateWindow ( std::string_view title, int2 size, WindowFlags windowFlags, OSWindowHandle parentOSHandle )

overridevirtual

Creates a window whose client area is size pixels, placed by the OS.

parentOSHandle is the owner window, or nullptr for a top-level one. Returns nullptr on failure.

Implements tachyon::IWindowBackend.

CreateWindow() [2/2]

OSWindowHandle tachyon::ImageWindowBackend::CreateWindow ( std::string_view title, IntRect rect, WindowFlags windowFlags, OSWindowHandle parentOSHandle )

overridevirtual

Creates a window whose client area is rect (screen pixels); otherwise as the size overload.

Implements tachyon::IWindowBackend.

DestroyWindow()

bool tachyon::ImageWindowBackend::DestroyWindow ( OSWindowHandle window )

overridevirtual

Queues the window for destruction: the next PollEvents passes its context to cleanup, then destroys it.

False for a handle that isn't one of the backend's windows.

Implements tachyon::IWindowBackend.

AttachInputHandlerToWindow()

void tachyon::ImageWindowBackend::AttachInputHandlerToWindow ( OSWindowHandle window, IPlatformInputHandler * inputHandler )

overridevirtual

Where the window's input goes (see IPlatformInputHandler); not owned, nullptr for none.

Implements tachyon::IWindowBackend.

AttachContextToWindow()

void tachyon::ImageWindowBackend::AttachContextToWindow ( OSWindowHandle window, IWindowContext * context )

overridevirtual

Stores the window's context (not owned), for GetWindowContext, for the ID passed with the window's input, and for PollEvents' cleanup.

nullptr clears it.

Implements tachyon::IWindowBackend.

DetachWindowContext()

void tachyon::ImageWindowBackend::DetachWindowContext ( OSWindowHandle window )

overridevirtual

Clears the context pointer stored in the OS window, so PollEvents' cleanup callback gets nullptr instead of double-freeing a context the caller destroys.

Implements tachyon::IWindowBackend.

IsWindow()

bool tachyon::ImageWindowBackend::IsWindow ( OSWindowHandle window )

overridevirtual

True while the handle is a live window of this backend; false once it was destroyed (by code or the user) and for nullptr.

Implements tachyon::IWindowBackend.

GetWindowContext()

IWindowContext * tachyon::ImageWindowBackend::GetWindowContext ( OSWindowHandle window )

overridevirtual

The context attached with AttachContextToWindow, or nullptr.

Implements tachyon::IWindowBackend.

BringToFront()

void tachyon::ImageWindowBackend::BringToFront ( OSWindowHandle window )

overridevirtual

Raises the window above the others and asks the OS for the input focus.

Implements tachyon::IWindowBackend.

GetWindowUnderMouse()

OSWindowHandle tachyon::ImageWindowBackend::GetWindowUnderMouse ( )

overridevirtual

The backend's window under the mouse, or nullptr.

Implements tachyon::IWindowBackend.

GetActiveWindow()

OSWindowHandle tachyon::ImageWindowBackend::GetActiveWindow ( )

overridevirtual

The window with the keyboard focus, or nullptr when none of the backend's windows has it.

Implements tachyon::IWindowBackend.

GetFocusChangeCount()

uint32_t tachyon::ImageWindowBackend::GetFocusChangeCount ( ) const

inlineoverridevirtual

Goes up whenever keyboard focus moves between windows, or to or from another application; open popups are checked against it.

Implements tachyon::IWindowBackend.

PollEvents()

void tachyon::ImageWindowBackend::PollEvents ( std::function< void(OSWindowHandle, IWindowContext *)> cleanup )

overridevirtual

Handles the OS's pending events, delivering input to the attached handlers.

Then the windows destroyed since the last call (DestroyWindow, or closed by the OS) go: cleanup gets each handle and its context while the window still exists. Runs in UpdateFrame, and again in RecordFrame.

Implements tachyon::IWindowBackend.

GetScreenMousePos()

int2 tachyon::ImageWindowBackend::GetScreenMousePos ( )

overridevirtual

The mouse position in screen pixels (SDL: as of the last PollEvents).

Implements tachyon::IWindowBackend.

ReadScreenPixel()

std::optional< color4b > tachyon::ImageWindowBackend::ReadScreenPixel ( int2 screenPos )

inlineoverridevirtual

The color of a screen pixel, anywhere on the desktop (an eyedropper); nothing where the platform can't read the screen.

Reimplemented from tachyon::IWindowBackend.

TakeCloseRequest()

bool tachyon::ImageWindowBackend::TakeCloseRequest ( OSWindowHandle window )

inlineoverridevirtual

Whether the OS asked to close a WindowFlags::ConfirmClose window since last asked.

Reimplemented from tachyon::IWindowBackend.

GetMouseButtons()

MouseButtons tachyon::ImageWindowBackend::GetMouseButtons ( )

overridevirtual

The mouse buttons held down, wherever the mouse is (SDL: as of the last PollEvents).

Implements tachyon::IWindowBackend.

SetCursor()

void tachyon::ImageWindowBackend::SetCursor ( MouseCursor cursor )

overridevirtual

Shows the system cursor for that shape; MouseCursor::None hides the cursor.

The library sets it once per frame.

Implements tachyon::IWindowBackend.

SetTextInputArea()

void tachyon::ImageWindowBackend::SetTextInputArea ( OSWindowHandle window, IntRect rect )

overridevirtual

Where text is being typed in the window (window coordinates), so the IME places its candidate list next to it.

Implements tachyon::IWindowBackend.

GetWindowDisplayScale()

float tachyon::ImageWindowBackend::GetWindowDisplayScale ( OSWindowHandle window )

overridevirtual

The UI scale the OS asks for in this window: pixel density times the monitor's content scale (1.5 on a 150% display).

0 when unknown.

Implements tachyon::IWindowBackend.

GetWindowPixelRect()

IntRect tachyon::ImageWindowBackend::GetWindowPixelRect ( OSWindowHandle window )

overridevirtual

The window's render target: OS position (for OS compositing) and size in physical pixels.

Implements tachyon::IWindowBackend.

SwapBuffers()

void tachyon::ImageWindowBackend::SwapBuffers ( OSWindowHandle window )

overridevirtual

Presents for a graphics API that swaps through the window (OpenGL).

The library doesn't call it: a Vulkan window context presents itself.

Implements tachyon::IWindowBackend.

GetWindowRect()

IntRect tachyon::ImageWindowBackend::GetWindowRect ( OSWindowHandle window )

overridevirtual

Client area in pixels; {0,0,0,0} while minimized.

Implements tachyon::IWindowBackend.

GetWindowPos()

int2 tachyon::ImageWindowBackend::GetWindowPos ( OSWindowHandle window )

overridevirtual

The client area's top-left in screen pixels.

Implements tachyon::IWindowBackend.

GetWindowSize()

int2 tachyon::ImageWindowBackend::GetWindowSize ( OSWindowHandle window )

overridevirtual

The client area's size in pixels; {0,0} while minimized.

Implements tachyon::IWindowBackend.

GetNativeHandle()

void * tachyon::ImageWindowBackend::GetNativeHandle ( OSWindowHandle window )

overridevirtual

The OS's own window handle, passed to GraphicsContext::CreateWindowContext (HWND on Windows, NSWindow on macOS, an X11 window or Wayland surface on Linux); nullptr without one.

Implements tachyon::IWindowBackend.

SetWindowRect()

bool tachyon::ImageWindowBackend::SetWindowRect ( OSWindowHandle window, const IntRect & clientRect )

overridevirtual

Moves and resizes the window so its client area is clientRect (screen pixels); the backend accounts for the frame.

True on success.

Implements tachyon::IWindowBackend.

SetWindowVisible()

void tachyon::ImageWindowBackend::SetWindowVisible ( OSWindowHandle window, bool visible )

overridevirtual

Shows or hides the window; hiding doesn't destroy it.

Implements tachyon::IWindowBackend.

SetWindowMode()

void tachyon::ImageWindowBackend::SetWindowMode ( OSWindowHandle window, WindowMode mode )

inlineoverridevirtual

Sets the window's state: minimized, maximized, restored or fullscreen.

The default does nothing.

Reimplemented from tachyon::IWindowBackend.

GetWindowMode()

WindowMode tachyon::ImageWindowBackend::GetWindowMode ( OSWindowHandle window ) const

inlineoverridevirtual

The window's state as the OS has it now; WindowMode::Normal by default.

Reimplemented from tachyon::IWindowBackend.

GetMonitors()

std::vector< MonitorInfo > tachyon::ImageWindowBackend::GetMonitors ( ) const

overridevirtual

Every monitor, the primary first.

Implements tachyon::IWindowBackend.

GetMonitorAt()

int tachyon::ImageWindowBackend::GetMonitorAt ( int2 pos ) const

overridevirtual

Index into GetMonitors of the monitor holding the screen point pos; 0 (the primary) when no monitor holds it, -1 without monitors.

Implements tachyon::IWindowBackend.

GetMonitorFromWindow()

int tachyon::ImageWindowBackend::GetMonitorFromWindow ( OSWindowHandle handle ) const

overridevirtual

Index into GetMonitors of the window's monitor; -1 for an unknown window.

Implements tachyon::IWindowBackend.

GetTicks()

uint32_t tachyon::ImageWindowBackend::GetTicks ( ) const

overridevirtual

A millisecond clock (SDL: since SDL started).

Implements tachyon::IWindowBackend.

GetPreferredLanguage()

std::string tachyon::ImageWindowBackend::GetPreferredLanguage ( ) const

overridevirtual

The user's preferred language as a BCP 47 tag ("ja", "en-US"), or empty when the platform doesn't say.

Reimplemented from tachyon::IWindowBackend.

GetCursorSize()

int32_t tachyon::ImageWindowBackend::GetCursorSize ( ) const

overridevirtual

The OS mouse cursor's size in pixels (its accessibility size at the display's scale), or 0 when the platform doesn't say.

Reimplemented from tachyon::IWindowBackend.

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

• gui_core/windows/gui_image_window_backend.h