I have a WebCanvas in a container. I am trying to work out the proper calculation to set the vertical Y coordinate to 0 at the top of the canvas on mousedown to work like a desktop canvas. Thanks for any help.
The top coordinate of the canvas is already zero.
Can you give a little more info about what you are trying to accomplish?
The X coordinate is 0 but the Y coordinate appears to be a different calculation. When I mousedown at the top left corner of the WebCanvas I get 0 for X and -815 for y. For the WebCanvas top I get 899. If I scroll the WebCanvas to the very top of the screen the top left Y coordinate is -899 on mousedown.
The WebCanvas height is 150. I want to calculate the top left Y coordinate to 0 and bottom left y coordinate to be the total height of the WebCanvas on mousedown.
After further investigation I have found this issue I am facing is caused by having the WebCanvas inside of a container that is placed on the WebPage.
If I add the WebCanvas to the page outside of the container it is as you said top left Y coordinate is 0.
Any thoughts on how to calculate this Y coordinate for a WebCanvas inside of a container?
Which control & event are you using to get the y coordinate from?
Huh… well that shouldnt be. Could you put together a sample and file a bug report in Feedback so I can look at it?
Are you by any chance putting that canvas inside of a container such that it can be scrolled vertically?
Yes I can do that.
The Container itself is set to Scrollbars Visible Automatic and the height is large enough that the WebPage has a scrollbar.
I got the Y coordinate finally by scrolling the canvas to the top of the container where I could predict the canvas.top by using container.top.
But now the MouseUp event is not firing for the WebCanvas…
@Geoff Haynes - Could you give me an idea of what you are trying to do with the WebCanvas? Just in case there’s a better way to approach this?
Nevermind for some reason mouseup is working now after I removed and re-added the container to the web page.
Thanks for your help Greg.
@Greg O’Lone Should I still file that bug report or did you conclude that the issue I was facing for a WebCanvas inside of a container was due to the container being scrolled vertically?
The ContentScrolled event was the answer I was looking for. By converting the negative Y axis value of the WebCanvas to a positive value and subtracting it from the value for the Y axis from ContentScrolled I can always find the 0 y value for the top left corner of the WebCanvas inside of a scrollable container.
In WebCanvas MouseDown.
Dim surf As RGBSurface = pColorPicker.RGBSurface txtBackColor.Text = "#" + str(surf.pixel(x, intScrollY - ABS(y))).right(6) cPick = surf.pixel(x, intScrollY - ABS(y))