No. But thanks. :-)
I am sending a REDRAW_THE_CANVAS message right now. I don't like that. See, in Windows, when I write a bunch of characters to the canvas, it doesn't redraw after each character, or if it does, it stops the redraw once you write to it again because it's fast.

Under Linux, I am telling it to redraw when I'm done sending all the text. There must be a method in Windows for controlling this, like only draw the canvas (if needed) every 500 ms or something. If I write 200 characters to the canvas, I don't want it to actually update the screen until
1) I'm done drawing
or
2) There is a pause in the drawing..

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In windows, when uou write characters to the canvas it is an instantaneous change to that canvas. The canvas is a context of some actual device, either the screen, or a bitmap or a metafile.

If the canvas is a screen canvas then the changes take place on screen. The operation is just a *change* and anything that may have already been there is not re-done.

Generally screen canvas's are painted in response to a WM_PAINT message. Any canvas paints which are done in other circumstances are non-permanant changes and will not be there next time the screen is pained because of WM_PAINT. (Usually there is nothing persistant about a screen image). A few controls do paint outside of WM_PAINT, mainly where: a) There are lots of small changes in a small area b) These small changes are also included in the WM_PAINT updates

examples are TEDIT and TMEMO controls.

In delphi, this is what InvalidateWindow is for.
Refresh is an Invalidate+Update which is not what you want.

A mere InvalidateWindow will tell windows that the window needs painting. Then, when there are no more other messages, windows will send out the WM_PAINT and then the window is painted.

The general method from your point of view is probably NOT to paint the window in response to key-strokes and stuff, but to instead update edit buffers and other structures so that when the paint message comes along you can paint the invalid'd region of the window.

Maybe GTK doesn't support idle anyway, but [I hate to say it] lots of Delphi stuff relies on it, so we should simulate it some way.

Does this make sense?

Sam

Anyone know of a good way of detecting WHEN to redraw the canvas? I don't want to redraw it each time it changes because if I write to it 200 times in a row, I don't want it to redraw 200 times. I want it to redraw after it's idle.

I thought of making each canvas have a timer in it that's reset on any type of drawing to the canvas, but that's kind of a generic method...

Thoughts...?
------------------------------------------------------------ Shane Miller

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Shane Miller wrote

Anyone know of a good way of detecting WHEN to redraw the canvas?

It is possible to block events and signals. You can put a block on it, do whatever you need to do, and then turn the block off. That way it will only do an update once after you turn the block off. I think that is what you are after isn't it?