I have two questions regarding Lazarus applications on Linux (Ubuntu 18 Mate):

1) Clipboard content erased on close?
I have an application with a form where the form size anmd position is stored into the clipboard on form close using a method of the form. This method is also called on form resize.
The problem is that while the application runs the resize operations cause the clipboard to be set up with the form size and it can be pasted elsewhere.
But when the app is closed and the same function is called to save the size to the clipboard the result is empty. Nothing to paste in another application..
Is this how it must be on Linux?
On Windows the clipboard content is not erased...

2) Is there a way to make forms transparent on Linux? Using the AlphaBlend and AlphaBlendValue do not wor while they do on Windows.
Is there some other way on Linux to make the form body transparent? I need to see the background through it since I want to "measure" the object by moving the form on top and adjusting its size to fit.

I also only learned this quite recently and was surprised by this, but yes, that is unfortunately how it works on X11. Pasting basically asks the application that "copied" it to get the content. If that app is gone in the meantime, there's nothing to paste anymore.

This will likely change with Wayland, but then it will also need some unified API, which there is not yet, afaik.

On Mon, Nov 30, 2020 at 8:12 PM Andreas Schneider via lazarus <

Proper desktop systems have a clipboard manager which caches the data and essentially makes clipboard persistent.
At least my KDE Plasma has it. An app in the taskbar also shows clipboard history which can be browsed and selected. Thus it is better than a traditional clipboard.

I recommend such versatile desktops for anybody. At least KDE Plasma has been optimized over time and is now slim and fast. Memory consumption is not really more than with XFCE.
Once a user opens Firefox, it hogs more memory than any desktop, thus overturning any benefits a minimal desktop might have given.

Juha
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Juha Manninen wrote

Once a user opens Firefox, it hogs more memory than any desktop, thus overturning any benefits a minimal desktop might have given.

+1
On Windows I have to regularly shut down all instances of FireFox with all of the tabs saved to a bookmark folder in order to clean up networking.
It seems like FFx not only steals memory but also messes with networking so that it is like "pouring molasses" over it...

Any ideas about transparent forms allowing look-through on Linux? Works in Windows, but...

On Mon, Nov 30, 2020 at 11:52 PM Bo Berglund via lazarus <

In Fedora with KDE , if you press the left mouse button when the cursor is on the taskbar of a Lazarus form ( and all of the other open windows of applications ) it becomes transparent to be sufficient to see the underside of it .

Mehmet Erol Sanliturk
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On Tue, Dec 1, 2020 at 12:02 AM Mehmet Erol Sanliturk <

I am sorry , not "taskbar`" but the "title bar" ...

Mehmet Erol Sanliturk

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On Mon, Nov 30, 2020 at 3:34 PM Bo Berglund via lazarus <

AlphaBlend + AlphaBlendValue work here with both GTK2 and QT5 bindings. It must be a Mate issue in your case.

Juha
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Mehmet Erol Sanliturk wrote

In Fedora with KDE , if you press the left mouse button when the cursor is on the title bar of a Lazarus form ( and all of the other open windows of applications ) it becomes transparent to be sufficient to see the underside of it .

Not so in Ubuntu Mate...