[Qt] [SOLVED] Link failure (undefined reference to `QFileDialog_selectFilter')

Laird lairdshaw77 at gmail.com
Mon Dec 26 16:17:13 CET 2011


On 21/12/11 18:59, zeljko wrote:
> What issue with scrollbars ?

Sorry about the delayed response - it took me a while to isolate the 
problem, and I was distracted by other things.

The problem seems to occur in the following minimal scenario: a form 
whose AutoScroll property is set to true, which contains a TStatusBar 
component and a client-aligned descendant of a TScrollBox component. 
The TScrollBox descendant - let's call it a TScrollBoxWithPanel - 
instantiates on its creation a TPanel component and sets that panel's 
parent to itself; its protected Resize procedure is overridden with the 
following code, where FPanel is the private property of 
TScrollBoxWithPanel used to store the created TPanel component:

   inherited;
   FPanel.Height := ClientHeight;

This scenario caused various problems depending on widgetset.

My mention of scrollbars in my last email referred to problems under the 
gtk2 widgetset: when the form is shrunk, form scrollbars appear and the 
TScrollBox component does not resize; when the form is resized past its 
"full scroll" width/height, then the scrollbars disappear again and the 
TScrollBox component resizes (by expanding) to client properly.

Under the qt widgetset, no scrollbars ever appear, but otherwise the 
behaviour is the same as under the gtk2 widgetset (i.e. when shrinking 
the form, the TScrollBox component does not resize, such that the status 
bar becomes hidden, and when the form is resized past its "full scroll" 
width/height, the TScrollBox component resizes to client properly and 
the status bar becomes visible again).  Also, though, on initial display 
of the form, the bottom of the status bar is truncated; adding a 
TMainMenu component with at least one menu item results in even more of 
the bottom of the status bar being truncated.  With or without the 
TMainMenu component, though, increasing the form's height reveals the 
hitherto truncated bottom of the status bar.

Setting the form's AutoScroll property to false "fixes" this behaviour 
under both widgetsets: in other words, scrollbars never appear, the 
TScrollBoxWithPanel component aligns to client and resizes properly, and 
the status bar is always visible and its bottom is never truncated.

I hope that answers your question - please let me know if you'd like 
more information.

Laird




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