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gtk1+2 intf: limit Gtk2RangeScrollCB to maximum

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git-svn-id: trunk@21505 -
This commit is contained in:
mattias 2009-08-31 20:21:50 +00:00
parent 56223815cd
commit ee7a5a1f0f
1 changed files with 31 additions and 0 deletions
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31
lcl/interfaces/gtk2/gtk2wscontrols.pp
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@ -121,8 +121,27 @@ function Gtk2RangeScrollCB(ARange: PGtkRange; AScrollType: TGtkScrollType;
AValue: gdouble; AWidgetInfo: PWidgetInfo): gboolean; cdecl;
var
Msg: TLMVScroll;
MaxValue: gdouble;
ScrolledBeyondMaximum: Boolean;
begin
Result := CallBackDefaultReturn;
ScrolledBeyondMaximum:=false;
if (ARange^.adjustment<>nil) then begin
MaxValue:=ARange^.adjustment^.upper-Max(ARange^.adjustment^.page_size-1,0);
//debugln(['Gtk2RangeScrollCB AValue=',AValue,' MaxValue=',MaxValue]);
if AValue>MaxValue then begin
// limit to maximum
ScrolledBeyondMaximum:=true;
AValue:=MaxValue;
if AValue=ARange^.adjustment^.value then begin
// already at maximum
Result:=not Result;
exit;
end;
end;
end;
//Assert(False, Format('Trace:[Gtk2RangeScrollCB] Value: %d', [RoundToInt(AValue)]));
if G_OBJECT_TYPE(ARange) = gtk_hscrollbar_get_type then
Msg.Msg := LM_HSCROLL
@ -140,6 +159,18 @@ begin
ScrollCode := GtkScrollTypeToScrollCode(AScrollType);
end;
Result := DeliverMessage(AWidgetInfo^.LCLObject, Msg) <> 0;
if (Result=CallBackDefaultReturn) and ScrolledBeyondMaximum
and (ARange^.adjustment<>nil) then begin
// scroll to maximum
// otherwise when dragging fast with the mouse the bar will not reach the maximum
MaxValue:=ARange^.adjustment^.upper-Max(ARange^.adjustment^.page_size-1,0);
if ARange^.adjustment^.value<>MaxValue then begin
ARange^.adjustment^.value:=MaxValue;
gtk_adjustment_changed(ARange^.adjustment);
end;
Result:=not Result;
end;
end;
function Gtk2ScrolledWindowScrollCB(AScrollWindow: PGtkScrolledWindow; AEvent: PGdkEventScroll; AWidgetInfo: PWidgetInfo): gboolean; cdecl;