LCL: implemented Application.TaskBarBehavior, bug #13537

git-svn-id: trunk@24682 -

lcl/forms.pp

@@ -491,6 +491,7 @@ type
                             const Handler: TMethod);
     function FindDefaultForActiveControl: TWinControl;
     procedure UpdateMenu;
+    procedure UpdateShowInTaskBar;
   protected
     FActionLists: TList; // keep this TList for Delphi compatibility
     FFormBorderStyle: TFormBorderStyle;
@@ -1140,6 +1141,12 @@ type
     sbgSystem   // show them depending on OS
   );
 
+  TTaskBarBehavior = (
+    tbDefault,      // widgetset dependent
+    tbMultiButton,  // show buttons for Forms with ShowTaskBar = stDefault
+    tbSingleButton  // hide buttons for Forms with ShowTaskBar = stDefault
+  );
+
   { TApplication }
 
   TApplication = class(TCustomApplication)
@@ -1207,6 +1214,7 @@ type
     FLastMouseControlValid: Boolean;
     FBidiMode: TBiDiMode;
     FRestoreStayOnTop: TList;
+    FTaskBarBehavior: TTaskBarBehavior;
     procedure DoOnIdleEnd;
     function GetActive: boolean;
     function GetCurrentHelpFile: string;
@@ -1220,6 +1228,7 @@ type
     procedure SetNavigation(const AValue: TApplicationNavigationOptions);
     procedure SetShowButtonGlyphs(const AValue: TApplicationShowGlyphs);
     procedure SetShowMenuGlyphs(const AValue: TApplicationShowGlyphs);
+    procedure SetTaskBarBehavior(const AValue: TTaskBarBehavior);
     procedure UpdateMouseControl(NewMouseControl: TControl);
     procedure UpdateMouseHint(CurrentControl: TControl);
     procedure SetCaptureExceptions(const AValue: boolean);
@@ -1390,6 +1399,7 @@ type
     property MainForm: TForm read FMainForm;
     property ModalLevel: Integer read FModalLevel;
     property MouseControl: TControl read FMouseControl;
+    property TaskBarBehavior: TTaskBarBehavior read FTaskBarBehavior write SetTaskBarBehavior;
     property OnActionExecute: TActionEvent read FOnActionExecute write FOnActionExecute;
     property OnActionUpdate: TActionEvent read FOnActionUpdate write FOnActionUpdate;
     property OnActivate: TNotifyEvent read FOnActivate write FOnActivate;

lcl/include/application.inc

@@ -526,6 +526,21 @@ begin
   NotifyCustomForms(CM_APPSHOWMENUGLYPHCHANGED);
 end;
 
+procedure TApplication.SetTaskBarBehavior(const AValue: TTaskBarBehavior);
+var
+  i: Integer;
+  FormToUpdate: TCustomForm;
+begin
+  if FTaskBarBehavior=AValue then exit;
+  FTaskBarBehavior:=AValue;
+  for i := 0 to Screen.CustomFormCount-1 do
+  begin
+    FormToUpdate := Screen.CustomForms[i];
+    if FormToUpdate.ShowInTaskBar = stDefault then
+      FormToUpdate.UpdateShowInTaskBar;
+  end;
+end;
+
 {------------------------------------------------------------------------------
   procedure TApplication.UpdateMouseControl(NewMouseControl: TControl);
 
@@ -903,9 +918,17 @@ end;
  ------------------------------------------------------------------------------}
 procedure TApplication.UpdateVisible;
 
+  function AppUseSingleButton: Boolean;
+  begin
+    Result := (TaskBarBehavior = tbSingleButton)
+      or ((TaskBarBehavior = tbDefault)
+      and (WidgetSet.GetLCLCapability(lcNeedMininimizeAppWithMainForm) = LCL_CAPABILITY_YES));
+  end;
+
   function UseAppTaskbarItem(AForm: TCustomForm): Boolean; inline;
   begin
-    Result := (AForm = MainForm) or (AForm.ShowInTaskBar in [stNever, stDefault]);
+    Result := (AForm = MainForm) or (AForm.ShowInTaskBar = stNever)
+      or ((AForm.ShowInTaskBar = stDefault) and AppUseSingleButton);
   end;
 
   function HasVisibleForms: Boolean;

lcl/include/customform.inc

@@ -490,6 +490,15 @@ begin
 
   Activate;
   if Application <> nil then Application.Activate;
+  // The button reappears in some situations (e.g. when the window gets the
+  //"urgency" flag) so we hide it again here.
+  // This is the most important place to invoke UpdateShowInTaskBar, since
+  //invoking it anywhere else seeems basically useless/frequently reversed.
+  if (ShowInTaskBar = stNever) or ((ShowInTaskBar = stDefault)
+    and (Application.TaskBarBehavior = tbSingleButton)) then
+  begin
+    UpdateShowInTaskBar;
+  end;
 end;
 
 {------------------------------------------------------------------------------
@@ -756,6 +765,21 @@ begin
   end;
 end;
 
+procedure TCustomForm.UpdateShowInTaskBar;
+var
+  Value: TShowInTaskBar;
+begin
+  if (Application.MainForm = Self) or (not HandleAllocated) then Exit;
+  Value := ShowInTaskBar;
+  if (Value = stDefault) or (csDesigning in ComponentState) then
+    case Application.TaskBarBehavior of
+      tbSingleButton: Value := stNever;
+      tbMultiButton: Value := stAlways;
+      else // nothing
+    end;
+  TWSCustomFormClass(WidgetSetClass).SetShowInTaskbar(Self, Value);
+end;
+
 class procedure TCustomForm.WSRegisterClass;
 begin
   inherited WSRegisterClass;
@@ -1758,8 +1782,7 @@ procedure TCustomForm.SetShowInTaskbar(Value: TShowInTaskbar);
 begin
   if Value = FShowInTaskbar then exit;
   FShowInTaskbar := Value;
-  if not (csDesigning in ComponentState) and HandleAllocated then
+  UpdateShowInTaskBar;
-    TWSCustomFormClass(WidgetSetClass).SetShowInTaskbar(Self, Value);
 end;
 
 {------------------------------------------------------------------------------
@@ -2295,6 +2318,7 @@ begin
 
   Assert(False, 'Trace:[TCustomForm.CreateWnd] FMenu.HandleNeeded');
   UpdateMenu;
+  UpdateShowInTaskBar;
 
   {$IFDEF OldAutoSize}
   // activate focus if visible

lcl/interfaces/gtk/gtkproc.inc

@@ -773,6 +773,13 @@ begin
     Enable := false;}
 
   //debugln('SetGtkWindowShowInTaskbar ',DbgSName(AForm),' ',dbgs(Enable));
+  // The button reappears in some (still unknown) situations, but has the
+  //'skip-taskbar-hint' property still set to True, so invoking the function
+  //doesn't have an effect. Resetting the property makes it work.
+  {$IFNDEF GTK1}
+  if (not Enable) and gtk_window_get_skip_taskbar_hint(PGtkWindow(Widget)) then
+    gtk_window_set_skip_taskbar_hint(PGtkWindow(Widget), False);
+  {$ENDIF}
   SetGtkWindowShowInTaskbar(PGtkWindow(Widget), Enable);
 end;
 

lcl/interfaces/gtk2/gtk2wsforms.pp

@@ -168,6 +168,10 @@ begin
     // create a floating form
     P := gtk_window_new(WindowType);
 
+    // This is done with the expectation to avoid the button blinking for forms
+    //that hide it, but currently it doesn't seem to make a difference.
+    gtk_window_set_skip_taskbar_hint(P, True);
+
     if (ABorderStyle = bsNone) and (ACustomForm.FormStyle in fsAllStayOnTop) then
       gtk_window_set_decorated(PGtkWindow(P), False);