Canvas.Paint problem

General
1

Hello,

Bellow is code where I drawing rectangles for my app.
Sub bellow is called from Canvas.Paint, where g is sent from Canvas.Paint as its Graphics.
rct() is declared as Graphics.
I am creating clip for each rectangle I draw.

Canvas object in window is resized to Window.height-15 and Window.width-15 and there is small label as status bar in bottom of window with height=15.

My problem is, when I resize window size (Canvas is also sized after resize), then my drawings is not ending at Canvas end but is overlapping to end of window and over label object.
As I understand drawings should ends at border of Canvas.
Here is screenshot how my rectangles are painted over label and out of Canvas.

[code]Sub DrawGuardOutline(i as integer, g as Graphics)

OvwData(i).X=ClipColumnOffset + ((ClipColumn-1)(ClipWidth+ClipColumnOffset))
OvwData(i).Y=ClipRowOffset + (ClipRow(ClipHeight+ClipRowOffset))
OvwData(i).Width=ClipWidth
OvwData(i).Height=ClipHeight

rct(i)=g.clip(OvwData(i).X,OvwData(i).Y,ClipWidth,ClipHeight)//Create Clip
rct(i).PenHeight=2
rct(i).PenWidth=2
rct(i).ForeColor=EventColor
rct(i).DrawRoundRect(0,0,rct(i).Width,rct(i).Height,7,7)//Draw Outline
rct(i).PenHeight=1
rct(i).PenWidth=1
rct(i).FillRoundRect(2,2,rct(i).Width-4,rct(i).Height-4,7,7)//Fill Rect
End Sub
[/code]

Any tips ?

Thanks

Martin

2

Make sure you have the right and bottom locks set for the canvas.

3

Hi Greg,

I had unchecked this, but enable of locks did not help.
I am resizing Canvas on each resize of parent window by code.

Weird is, but when I create non-resizeable small canvas 100x100 pixels I got entire rectangles painted outside of Canvas.
It looks like my rectangles are painted on Window background.
But Window.Paint method is empty.

Thanks

4

have you tried NOT doing that? let it resize itself by virtue of the fact you locked the corners in place

5

Tested now…not success with locked corners

6

Where are ClipWidth and ClipHeight set? Are they taking into account the current size using g.Width and g.Height?

7

ClipWidth and ClipHeight are set as Property in this window and Value is set in declaration.

ClipWidth As Integer=140

Here is screenshot of rectangles where I have Canvas non-resizable.
Grey is Canvas, Blue is Window Background.

Rectangles are out of Canvas.
Thanks

8

It looks as if the g that is being passed in is actually the Window’s graphics property, not the canvas.
I do wonder why you are using a clip?

If the canvas size is known, all you need do is draw rectangles on the canvas, at known positions.

Narrow things down:

In the canvas paint event, try
g.drawrect g.width + 10,g.height +10, 50,50

Does that draw on the window?

If it does, call a method, passing g
Then in the method use the line above.

Does THAT paint outside the canvas?

And finally, if it still doesn’t, change that method to create a clip, and try that.

After those steps, it will at least be clear where the trouble lies.

9

Hi Jeff,

You are right.
When I pass Graphics.Clip as parameter to Sub then Paint is done on Window background.
I recode it to not use CLIPs and rectangles are now correctly inside Canvas.

Reason why I used clips is, that I pass various objects and texts into rectangles and it was easier for coding to use coordinates of clip.
E.g. draw from position 0,0 etc…Now I will also need to refine code for checking of text length, because I have resizeable rectangles and longer text is outside of rectangle and clip solves it automatcally. (text was trimmed at clip edges)

Btw I think it should work also for clips. So maybe it is bug.

Thanks

Martin