TimelineCanvas Class Reference

Description

Definition at line 88 of file body-canvas-widget.hpp.

Public Member Functions
	TimelineCanvas (_Renderer groundingFun, _Renderer overlayFun)

Private Types
using	_Renderer = std::function< void(CairoC)>

Private Member Functions
void	closeCanvas (CairoC)
	Finish and close the virtual drawing canvas established by openCanvas(). More...
void	drawGrounding (CairoC)
	Establish and render the structure of (possibly nested) tracks and overview rulers. More...
void	drawOverlays (CairoC)
virtual bool	on_draw (CairoC) override
	Custom drawing of the timeline content area. More...
void	openCanvas (CairoC)
	Prepare the drawing canvas to work within our virtual canvas coordinate system. More...

Private Attributes
_Renderer	renderGrounding_
_Renderer	renderOverlay_

Member Function Documentation

on_draw()

bool on_draw ( CairoC  cox )

overrideprivatevirtual

Custom drawing of the timeline content area.

The inherited Gtk::Layout::on_draw(Context) handles all drawing of child widgets placed onto the virtual canvas. Thus we need to fill in the structure of the tracks in the timeline background, and any non-standard overlay elements, including tags and markers, indicators, locators (edit point and playhead) and (semi-transparent) range selections.

Todo:

according to the documentation for signal_draw(), the framework passes the actually visible area as clipping region. In theory, this information could be used to reduce the load of canvas painting and repainting, which becomes crucial for responsiveness on large sessions ////////////////////////////////////TICKET #1191

Definition at line 653 of file body-canvas-widget.cpp.

openCanvas()

void openCanvas ( CairoC  cox )

private

Prepare the drawing canvas to work within our virtual canvas coordinate system.

Remarks

GTK passes a context related to the actual window area; however, we need to create a uniform virtual canvas, shared by the child widgets, the backgrounding and any overlays. To make this work, we have to connect to the scrollbar adjustments, since GTK does this only for the child widgets on the canvas, not for any custom painting.

Definition at line 680 of file body-canvas-widget.cpp.

closeCanvas()

void closeCanvas ( CairoC  cox )

private

Finish and close the virtual drawing canvas established by openCanvas().

Discard any coordinate offsets, stroke and drawing settings applied within.

Definition at line 697 of file body-canvas-widget.cpp.

drawGrounding()

void drawGrounding ( CairoC  cox )

private

Establish and render the structure of (possibly nested) tracks and overview rulers.

Parameters

cox	cairo drawing context for custom drawing, adjusted for our virtual canvas.

Definition at line 708 of file body-canvas-widget.cpp.

drawOverlays()

void drawOverlays ( CairoC  cox )

private

Parameters

cox	cairo drawing context of the virtual canvas for custom drawing.

Definition at line 719 of file body-canvas-widget.cpp.

Inheritance diagram for TimelineCanvas:

Collaboration diagram for TimelineCanvas:

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

• body-canvas-widget.hpp
• body-canvas-widget.cpp