SourceEditor draws slowly over messages and main windows on Linux 64 bit

[Eugene Loza]

As strange as it may seem, when I drag "Source Editor" window it slows down significantly leaving "tracks" over Main window and Messages window which update only when mouse is stopped. Other windows (e.g. Terminal output window, Project inspector, Options) operate obviously correct, the same goes for Main window over Messages window. It's only the Source Editor that slows the things down. The slowdown appears even when there is only one tab is open (a new empty simple program to be more specific).

Lazarus 1.6.2 64 bit FPC 3.0.0
Debian Linux 64bit

Absolutely no problem with Lazarus 1.6.2 32 bit at Debian Linux 32bit at a much slower computer (32 bit 1.7 GHz * 1 score vs 64 bit 3.5 GHz * 8 core).

[Martin_fr]

To be clear:

You do not change the content of the Editor? (And you do not scroll, or otherwise change what is displayed inside the Editor?)

It is just dragging the SrcEdit Win, and the artifacts are left on the main or message window?
So that is that the main or msg window is not redrawn quick enough?

[Eugene Loza]

You do not change the content of the Editor? (And you do not scroll, or otherwise change what is displayed inside the Editor?)

No, just dragging it by mouse (catching by the titlebar).

It is just dragging the SrcEdit Win, and the artifacts are left on the main or message window?

The artefacts are left only while dragging. As soon as I stop dragging (even not releasing the mouse button, just stop motion) artefacts disappear immediately. But they remain while mouse pointer is moving. Moreover, the Source Editor position lags behind the mouse pointer. (Comparing to 32 bit version: in 32 bit Linux&Lazarus artefacts quickly disappear while dragging the Source Editor Window, and Source Editor Window doesn't lag behind mouse cursor).

So that is that the main or msg window is not redrawn quick enough?

Source editor window is displayed fine. But dragging it is slow (comparing to other Lazarus windows) and it leaves artefacts - only in case it is dragged on the top of Main Window or Message Window. When it's dragged in free space over desktop/other programs, over Terminal Output Window, over Assembler Window, over Object Inspector Window no slow-downs or artefacts appear.