gccv::Canvas Class Reference

the Canvas class More...

#include <gccv/canvas.h>

Public Member Functions
	Canvas (Client *client)
virtual	~Canvas ()
Item *	GetItemAt (double x, double y)
GtkWidget *	GetWidget ()
void	Invalidate (double x0, double y0, double x1, double y1)
void	SetBackgroundColor (GOColor color)
void	SetZoom (double zoom)
void	Render (cairo_t *cr, bool is_vector)
double	GetZoom (void) const
Group *	GetRoot (void) const
void	SetGap (double val)
double	GetGap (void) const
double &	GetRefGap (void)
GOColor	GetColor (void) const
GOColor	GetBackgroundColor (void) const
unsigned	GetLastEventState (void) const

Detailed Description

the Canvas class

This class is the container class for the items and is the only one interacting with the underlying Gtk+ framework. It uses a private widget derived from GtkDrawingArea.

Definition at line 53 of file canvas.h.

Constructor & Destructor Documentation

gccv::Canvas::Canvas

(

Client *

client

)

Parameters

client

the gccv::Client for the canvas or NULL.

Constructs a canvas for client which is mandatory if some interaction with the canvas is needed.

virtual gccv::Canvas::~Canvas ( )

virtual

The destructor. You should not delete the canvas, as it will be destroyed with the enclosing widget. Instead, if you never show the widget in a window, use:

gtk_widget_destroy (canvas->GetWidget ());

Items are stored in an ordered tree whose top node is a gccv::Group instance which can be accessed by the GetRoot() method.

Member Function Documentation

gccv::Canvas::GetBackgroundColor ( void  ) const

inline

Returns

the background color.

Definition at line 159 of file canvas.h.

gccv::Canvas::GetColor ( void  ) const

inline

Returns

the foreground color.

Definition at line 152 of file canvas.h.

gccv::Canvas::GetGap ( void  ) const

inline

Returns

the current gap for the canvas.

Definition at line 148 of file canvas.h.

Item* gccv::Canvas::GetItemAt	(	double	x,
		double	y
	)

Parameters

x	the x coordiante.
y	the y coordinate.

Used to get the top item at or near the given position.

Returns

the found item or NULL if no item is nearer than the current gap from the given position.

gccv::Canvas::GetLastEventState ( void  ) const

inline

Returns

the GdkModifierType value for the last received event.

Definition at line 163 of file canvas.h.

gccv::Canvas::GetRefGap ( void  )

inline

Returns

the current gap for the canvas as a reference.

Definition at line 148 of file canvas.h.

gccv::Canvas::GetRoot ( void  ) const

inline

Returns

the root item.

Definition at line 130 of file canvas.h.

GtkWidget* gccv::Canvas::GetWidget ( void  )

inline

Returns

the widget used by the canvas.

Definition at line 89 of file canvas.h.

gccv::Canvas::GetZoom ( void  ) const

inline

Returns

the current zoom level for the canvas.

Definition at line 126 of file canvas.h.

void gccv::Canvas::Invalidate	(	double	x0,
		double	y0,
		double	x1,
		double	y1
	)

Parameters

x0	the x coordinate for the top left of the invalidated rectangle.
y0	the y coordinate for the top left of the scrolling rectangle.
x1	the x coordinate for the bottom right of the scrolling rectangle.
y1	the y coordinate for the bottom right of the scrolling rectangle.

void gccv::Canvas::Render	(	cairo_t *	cr,
		bool	is_vector
	)

Parameters

cr	a cairo context.
is_vector	whether the cairo context is vectorial or raster.

Renders the current canvas to the cairo context.

void gccv::Canvas::SetBackgroundColor

(

GOColor

color

)

Parameters

color

a GOColor.

Sets the background color for the canvas widget

gccv::Canvas::SetGap ( double  gap )

inline

Parameters

gap	a distance at which an item might be from an event location to be selected for the event.

Sets the maximum distance at which an item might be from an event location to be selected for the event. When an even as a mouse button click occurs, and if it occurs on an item, the appropriate method of the item client will be called; else if it occurs on the background, the nearest item will be used if its distance from the event location is less than gap. If no item can be used, the event will have no associated gccv::ItemClient instance.

Definition at line 148 of file canvas.h.

void gccv::Canvas::SetZoom

(

double

zoom

)

Parameters

zoom	the new zoom level.

Sets the zoom level for the canvas.

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

• canvas.h