[Lazarus] Visual "uglyness" when creating TSynEdit @ runtime in my app

[luiz americo pereira camara]

The last code also has a also an undesired effect: Some controls. eg
Lazarus options form, are not displayed when show at first time


Luiz

2013/1/5 luiz americo pereira camara <luizmed at oi.com.br>:
> 2013/1/5 luiz americo pereira camara <luizmed at oi.com.br>:
>> 2013/1/5 Martin <lazarus at mfriebe.de>:
>>> On 05/01/2013 12:57, luiz americo pereira camara wrote:
>>>>
>>>> 2013/1/5 Martin <lazarus at mfriebe.de>:
>>>>>
>>>>> On 05/01/2013 11:19, luiz americo pereira camara wrote:
>>>>>>
>>>>>> Can you check (comment ShowScrollBar) if the paint you are seeing is
>>>>>> really from ShowScrollBar?
>>>>>
>>>>> This would not make sense?
>>>>>
>>>>> Nothing, except the scrollbars is painted (SynEdit does not paint).
>>>>
>>>> I understood that SynEdit.Paint was called when setting Parent in your
>>>> system, but seems this is not the case.
>>>>
>>>> Although in the description of Bart he sees the whole SynEdit painted.
>>>>
>>> I am sure he was mistaken:
>>>
>>>>   for a
>>>> brief moment you can see the TSynEdit,
>>>
>>>
>>> He would see the 2 scrollbars, and in the sort time he would not have paid
>>> attention to the absence of all else. Seing the 2 scrollbars *flicker* it is
>>> only natural to assume one saw the synedit flicker.
>>
>> OK.
>>
>> Now i see the issue. At runtime i could not notice the flicker and
>> there's no WM_PAINT message involved, only stepping with the debugger
>> is possible to see the control painted
>>
>> Try
>>
>> putting SWP_NOREDRAW in SetWindowPos
>>
>> It fixed here, but not sure of collateral effects
>
> The collateral effect is that if a control is hidden, it will be still
> be show until is there a new paint cycle
>
> I come with the below implementation that will have the following
> behavior. I could not find issues but needs more testing
>
> - When a control is hidden, it's redraw immediately as is today
> - When a control is show, its not redraw immediately. The window is
> invalidated and a paint message is queued
>
> class procedure TWin32WSWinControl.ShowHide(const AWinControl: TWinControl);
> const
>   VisibilityToFlag: array[Boolean] of UINT = (SWP_HIDEWINDOW,
> SWP_SHOWWINDOW or SWP_NOREDRAW);
> var
>   WinHandle: HWND;
>   WinVisible: Boolean;
> begin
>   WinHandle := AWinControl.Handle;
>   WinVisible := AWinControl.HandleObjectShouldBeVisible;
>   Windows.SetWindowPos(WinHandle, 0, 0, 0, 0, 0,
>     SWP_NOSIZE or SWP_NOMOVE or SWP_NOZORDER or SWP_NOACTIVATE or
> VisibilityToFlag[WinVisible]);
>   //invalidate the window so it can be painted after show
>   if WinVisible then
>     Windows.RedrawWindow(WinHandle, nil, 0, RDW_INVALIDATE or RDW_FRAME);
> end;
>
>
> Luiz