The async version of the mozPrintCallback API is working for printing output (it still has very rough edges, but it "works").
However, things don't work correctly for print-preview: As I open print-preview, I see the calls on the canvas, that are done immediately when the mozPrintCallback is called. The drawings performed against the canvas context with some delay don't show up in preview. If I scroll the preview window, the repainted area of the canvas show the updated/right content. Also, if the print preview loses focus, the canvas shows the actual content. It looks like the "redraw this (part of the) canvas, as something in it changed" doesn't work. I tried to figure out what's going wrong here, but I know to little about the Gecko layout/redraw code/handling and what I should look for :/ Here is what I got so far: * nsCanvasRenderingContext2D.mIsEntireFrameInvalid doesn't seem to get reset to false * I've forced to ignore `mIsEntireFrameInvalid` and let the call to `nsHTMLCanvasElement::InvalidateCanvasContent` happen. The `!GetPrimaryFrame()` evaluates to true and therefore the function returns early without telling the layer to update Can someone give me some pointers what to do here? A way to get around this issue is to draw the nsPageFrame after all the canvas elements inside this page have finished the mozPrintCallback. Rendering the canvas progressive in print preview has the advantage to display other parts of the page (e.g. "normal" DOM content) to the user already and let him look at the drawings, while they build up. Best, Julian _______________________________________________ dev-tech-layout mailing list [email protected] https://lists.mozilla.org/listinfo/dev-tech-layout
