gem::Canvas Class Reference

Drawing surface used by MapView for rendering. More...

Inheritance diagram for gem::Canvas:

Collaboration diagram for gem::Canvas:

Classes
struct	__allow_private_constructor

Public Member Functions
StrongPointer< Screen >	getScreen () const noexcept
	Get the parent screen.
Rect	getViewport () const noexcept
	Get view viewport in parent screen coordinates.
RectF	getViewportF () const noexcept
	Get screen viewport in parent screen ratio.
bool	handleKeyboardEvent (EKey key, EKeyAction action) noexcept
	Handles a keyboard event.
Canvas &	resize (const RectF &screenRatio) noexcept
	Resize the view.
int	captureAsImage (const String &filePath, Rect const &rect=Rect(), EImageFileFormat format=IFF_Jpeg) const noexcept
	Make a screen region capture of the current map in JPEG format.
int	captureAsImage (DataBuffer &buffer, Rect const &rect=Rect(), EImageFileFormat format=IFF_Jpeg) const noexcept
	Make a screen region capture of the current map in JPEG format.
Image	captureAsImage (Rect const &rect=Rect()) const noexcept
	Make a screen region capture of the current map in JPEG format.
bool	isView () const noexcept
	Deprecated.
bool	isMapView () const noexcept
	Check if canvas is a MapView object.
void	detach () noexcept
	Detach canvas from rendering process.

Static Public Member Functions
static StrongPointer< Canvas >	produce (StrongPointer< Screen > screen, const RectF &screenRatio, CanvasListener listener) noexcept
	Create a canvas object on the given screen.

Protected Types
using	Base = ApiObject<ICanvas, false>
	Base.

Detailed Description

Drawing surface used by MapView for rendering.

Represents the surface where shapes, overlays, and custom graphics can be drawn.Acts as the foundation for rendering in a MapView.

Member Function Documentation

captureAsImage() [1/3]

int gem::Canvas::captureAsImage ( const String & filePath, Rect const & rect = Rect(), EImageFileFormat format = IFF_Jpeg ) const

inlinenoexcept

Make a screen region capture of the current map in JPEG format.

No cursor/on-screen info is included.

Parameters

[in]	filePath	File path.
[in]	rect	The screen rectangle to capture. If ( 0, 0, 0, 0) is provided then the entire map screen is captured.
[in]	format	The image format, default Jpeg

Returns

0 if successful, otherwise an error code

captureAsImage() [2/3]

int gem::Canvas::captureAsImage ( DataBuffer & buffer, Rect const & rect = Rect(), EImageFileFormat format = IFF_Jpeg ) const

inlinenoexcept

Make a screen region capture of the current map in JPEG format.

No cursor/on-screen info is included.

Parameters

[in]	buffer	The buffer in which the capture is made.
[in]	rect	The screen rectangle to capture. If ( 0, 0, 0, 0) is provided then the entire map screen is captured.
[in]	format	The image format, default Jpeg

Returns

0 if successful, otherwise an error code

captureAsImage() [3/3]

Image gem::Canvas::captureAsImage ( Rect const & rect = Rect() ) const

inlinenoexcept

Make a screen region capture of the current map in JPEG format.

No cursor/on-screen info is included.

Parameters

[in]

rect

The screen rectangle to capture. If ( 0, 0, 0, 0) is provided then the entire map screen is captured.

Returns

The captured image

detach()

void gem::Canvas::detach ( )

inlinenoexcept

Detach canvas from rendering process.

If OpenGL context is not available anymore during canvas destruction, this method should be called when the context is still valid in order to do all needed cleanups

getScreen()

StrongPointer< Screen > gem::Canvas::getScreen ( ) const

inlinenoexcept

Get the parent screen.

Returns

The parent screen

getViewport()

Rect gem::Canvas::getViewport ( ) const

inlinenoexcept

Get view viewport in parent screen coordinates.

origin is always 0, 0

Returns

The view viewport

getViewportF()

RectF gem::Canvas::getViewportF ( ) const

inlinenoexcept

Get screen viewport in parent screen ratio.

origin is always 0, 0

Returns

The view viewport

handleKeyboardEvent()

bool gem::Canvas::handleKeyboardEvent ( EKey key, EKeyAction action )

inlinenoexcept

Handles a keyboard event.

Parameters

key	Type of key that was interacted with.
action	Type of action that was performed on key.

Returns

True if the canvas used the key action, in which case the UI should stop forwarding the key to other UI elements

isMapView()

bool gem::Canvas::isMapView ( ) const

inlinenoexcept

Check if canvas is a MapView object.

Returns

True if the canvas is a MapView object

isView()

bool gem::Canvas::isView ( ) const

inlinenoexcept

Deprecated.

Deprecated

Replaced by isMapView.

Returns

True if the canvas is a view

produce()

StrongPointer< Canvas > gem::Canvas::produce ( StrongPointer< Screen > screen, const RectF & screenRatio, CanvasListener listener )

inlinestaticnoexcept

Create a canvas object on the given screen.

Parameters

[in]	screen	The view's parent screen (reference to it held internally)
[in]	screenRatio	The viewport expressed in parent screen ratio
[in]	listener	The canvas listener

Returns

The canvas object

resize()

Canvas & gem::Canvas::resize ( const RectF & screenRatio )

inlinenoexcept

Resize the view.

Parameters

[in]

screenRatio

The new viewport expressed in parent screen ratio

Returns

The view object