LCL: TControlScrollBar: Visible is not the current state, but a flag to allow the widget to become visible, for Delphi compatibility, fixed calculating Range (the widget frame was added)

git-svn-id: trunk@29031 -

docs/xml/lcl/forms.xml

@@ -809,8 +809,10 @@ Reads or writes a flag to determine paging increment; default value is 80 pixels
       </element>
       <!-- property Visibility: published -->
       <element name="TControlScrollBar.Visible">
-        <short>Is the scroll bar visible?</short>
+        <short>Can the scroll bar be made visible?</short>
-        <descr>Reads or writes flag to determine visibility, and sets a flag if the property is stored</descr>
+        <descr>Reads or writes flag to determine visibility, and sets a flag if the property is stored.
+The Handle object (widget) is made visible if (Visible=true) and (Range&gt;Page).
+To get the current visible state of the widget use the method IsScrollBarVisible.</descr>
         <seealso/>
       </element>
       <!-- variable Visibility: private -->

lcl/forms.pp

@@ -86,7 +86,7 @@ type
 
   TControlScrollBar = class(TPersistent)
   private
-    FAutoRange : Longint;
+    FAutoRange : Longint; // = FRange - ClientSize, >=0
     FIncrement: TScrollBarInc;
     FKind: TScrollBarKind;
     FPage: TScrollBarInc;
@@ -107,7 +107,6 @@ type
     function GetRange: Integer; virtual;
     function GetSize: integer; virtual;
     function GetSmooth: Boolean; virtual;
-    function GetVisible: Boolean; virtual;
     function HandleAllocated: boolean; virtual;
     function IsRangeStored: boolean; virtual;
     procedure AutoCalcRange; virtual;
@@ -130,10 +129,12 @@ type
   {$endif}
     function GetHorzScrollBar: TControlScrollBar; virtual;
     function GetVertScrollBar: TControlScrollBar; virtual;
+  protected
+    function ScrollBarShouldBeVisible: Boolean; virtual; // should the widget be made visible?
   public
     constructor Create(AControl: TWinControl; AKind: TScrollBarKind);
     procedure Assign(Source: TPersistent); override;
-    function IsScrollBarVisible: Boolean; virtual;
+    function IsScrollBarVisible: Boolean; virtual; // returns current widget state
     function ScrollPos: Integer; virtual;
     property Kind: TScrollBarKind read FKind;
     function GetOtherScrollBar: TControlScrollBar;
@@ -148,7 +149,7 @@ type
     property Position: Integer read GetPosition write SetPosition default 0; // 0..Range-Page
     property Range: Integer read GetRange write SetRange stored IsRangeStored default 0; // >=Page
     property Tracking: Boolean read FTracking write SetTracking default False;
-    property Visible: Boolean read GetVisible write SetVisible default True;
+    property Visible: Boolean read FVisible write SetVisible default True;
   end;
 
   { TScrollingWinControl }
@@ -182,7 +183,6 @@ type
     constructor Create(TheOwner : TComponent); override;
     destructor Destroy; override;
     procedure UpdateScrollbars;
-    function HasVisibleScrollbars: boolean; virtual;
     class function GetControlClassDefaultSize: TSize; override;
     procedure ScrollBy(DeltaX, DeltaY: Integer);
   published
@@ -1590,6 +1590,7 @@ function WindowStateToStr(const State: TWindowState): string;
 function StrToWindowState(const Name: string): TWindowState;
 function dbgs(const State: TWindowState): string; overload;
 function dbgs(const Action: TCloseAction): string; overload;
+function dbgs(const Kind: TScrollBarKind): string; overload;
 
 type
   TFocusState = Pointer;
@@ -1772,6 +1773,14 @@ begin
   Result:=GetEnumName(TypeInfo(TCloseAction),ord(Action));
 end;
 
+function dbgs(const Kind: TScrollBarKind): string;
+begin
+  if Kind=sbVertical then
+    Result:='sbVertical'
+  else
+    Result:='sbHorizontal';
+end;
+
 //------------------------------------------------------------------------------
 function GetParentForm(Control: TControl): TCustomForm;
 begin

lcl/include/controlscrollbar.inc

@@ -93,7 +93,7 @@ begin
     ScrollInfo.fMask := SIF_POS;
     ScrollInfo.nPos := FPosition;
 
-    FPosition := SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, FVisible);
+    FPosition := SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, ScrollBarShouldBeVisible);
   end;
 end;
 
@@ -110,8 +110,11 @@ begin
   begin
     ScrollInfo.fMask := SIF_PAGE;
     GetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo);
-    InvalidateScrollInfo;
+    if FPage<>ScrollInfo.nPage then
-    FPage := ScrollInfo.nPage;
+    begin
+      FPage := ScrollInfo.nPage;
+      InvalidateScrollInfo;
+    end;
   end;
   Result := FPage;
 end;
@@ -124,8 +127,11 @@ begin
   begin
     ScrollInfo.fMask := SIF_POS;
     GetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo);
-    InvalidateScrollInfo;
+    if FPosition<>ScrollInfo.nPos then
-    FPosition := ScrollInfo.nPos;
+    begin
+      FPosition := ScrollInfo.nPos;
+      InvalidateScrollInfo;
+    end;
   end;
   Result := FPosition;
 end;
@@ -133,13 +139,18 @@ end;
 function TControlScrollBar.GetRange: Integer;
 var
   ScrollInfo: TScrollInfo;
+  NewRange: Integer;
 begin
   if HandleAllocated and (not (FControl is TScrollingWinControl)) then
   begin
     ScrollInfo.fMask := SIF_Range + SIF_Page;
     GetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo);
-    InvalidateScrollInfo;
+    NewRange := ScrollInfo.nMax - ScrollInfo.nMin;
-    FRange := ScrollInfo.nMax - ScrollInfo.nMin;
+    if NewRange<>FRange then
+    begin
+      FRange:=NewRange;
+      InvalidateScrollInfo;
+    end;
   end;
   Result := FRange;
 end;
@@ -149,16 +160,6 @@ begin
   Result := FSmooth;
 end;
 
-function TControlScrollBar.GetVisible: Boolean;
-begin
-  if HandleAllocated and (not (FControl is TScrollingWinControl)) then
-  begin
-    InvalidateScrollInfo;
-    FVisible := GetScrollbarVisible(Controlhandle, IntfBarKind[Kind]);
-  end;
-  Result := FVisible;
-end;
-
 procedure TControlScrollBar.SetIncrement(const AValue: TScrollBarInc);
 begin
   // This value is only used by the ScrollHandler procedure
@@ -181,10 +182,8 @@ begin
   else
     KindID := SM_CXVSCROLL;
   if HandleAllocated then
-  begin
+    Result := LCLIntf.GetScrollBarSize(ControlHandle,KindID)
-    Result := LCLIntf.GetScrollBarSize(ControlHandle,KindID);
+  else
-    InvalidateScrollInfo;
-  end else
     Result := GetSystemMetrics(KindID);
 end;
 
@@ -226,13 +225,18 @@ procedure TControlScrollBar.AutoCalcRange;
   end;
 
   procedure GetPreferredClientRect(out PreferredWidth, PreferredHeight: integer);
+  var
+    CurClientRect: TRect;
   begin
     PreferredWidth:=0;
     PreferredHeight:=0;
-    FControl.GetPreferredSize(PreferredWidth,PreferredHeight,true);
+    FControl.GetPreferredSize(PreferredWidth,PreferredHeight,true,false);
-    //DebugLn(['GetPreferredClientRect ',DbgSName(FControl),' Pref=',PreferredWidth,'x',PreferredHeight]);
+    CurClientRect := FControl.ClientRect;
-    if PreferredWidth<0 then PreferredWidth:=0;
+    if PreferredWidth>0 then
-    if PreferredHeight<0 then PreferredHeight:=0;
+      PreferredWidth:=Max(0,PreferredWidth-(FControl.Width-CurClientRect.Right));
+    if PreferredHeight>0 then
+      PreferredHeight:=Max(0,PreferredHeight-(FControl.Height-CurClientRect.Bottom));
+    //DebugLn(['GetPreferredClientRect ',DbgSName(FControl),' PrefClient=',PreferredWidth,'x',PreferredHeight]);
   end;
 
   procedure AutoCalcVRange;
@@ -252,7 +256,7 @@ procedure TControlScrollBar.AutoCalcRange;
   begin
     GetPreferredClientRect(PreferredWidth,PreferredHeight);
     //if FControl.ClassName='TEditorCodetoolsOptionsFrame' then
-    //  DebugLn(['AutoCalcHRange ',DbgSName(FControl),' AutoSize=',FControl.AutoSize,' Bounds=',dbgs(FControl.BoundsRect),' Client=',dbgs(FControl.ClientRect),' pref=',PreferredWidth,'x',PreferredHeight]);
+      //DebugLn(['AutoCalcHRange ',DbgSName(FControl),' AutoSize=',FControl.AutoSize,' Bounds=',dbgs(FControl.BoundsRect),' Client=',dbgs(FControl.ClientRect),' pref=',PreferredWidth,'x',PreferredHeight]);
     InternalSetRange(PreferredWidth);
   end;
 
@@ -282,21 +286,21 @@ begin
     ScrollInfo.nPos := FPosition;
     ScrollInfo.nPage := FPage;
     ScrollInfo.nTrackPos := FPosition;
+    NewVisible := ScrollBarShouldBeVisible;
     if (not FOldScrollInfoValid) or (not CompareMem(@ScrollInfo, @FOldScrollInfo, SizeOf(TScrollInfo))) then
     begin
       FOldScrollInfo := ScrollInfo;
       FOldScrollInfoValid := True;
-      SetScrollInfo(FControl.Handle, IntfBarKind[Kind], ScrollInfo, FVisible);
+      SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, NewVisible);
       // update policy too
       ScrollInfo.fMask := SIF_UPDATEPOLICY;
       ScrollInfo.nTrackPos := TrackToPolicyMap[FTracking];
-      SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, FVisible);
+      SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, NewVisible);
     end;
-    NewVisible := Visible and (ScrollInfo.nMax > ScrollInfo.nPage);
     ShowScrollBar(FControl.Handle, IntfBarKind[Kind], NewVisible);
     {$IFDEF VerboseScrollingWinControl}
     if DebugCondition then
-      DebugLn(['TControlScrollBar.UpdateScrollBar ',DbgSName(FControl),' ',DbgSName(Self),' FVisible=',FVisible,' Range=',FRange,' FPosition=',FPosition,' FPage=',FPage,' FAutoRange=',FAutoRange]);
+      DebugLn(['TControlScrollBar.UpdateScrollBar ',DbgSName(FControl),' ',DbgSName(Self),' FVisible=',FVisible,' Range=',FRange,' FPosition=',FPosition,' FPage=',FPage,' FAutoRange=',FAutoRange,' ShouldVisible=',NewVisible]);
     {$ENDIF}
   end;
 
@@ -399,8 +403,8 @@ begin
     Exit;
   FRange := AValue;
   {$IFDEF VerboseScrollingWinControl}
-  if DebugCondition then
+  //if DebugCondition then
-    DebugLn(['TControlScrollBar.SetRange ',Self,' fRange=',FRange]);
+    DebugLn(['TControlScrollBar.SetRange ',dbgs(Kind),' ',Self,' fRange=',FRange]);
   {$ENDIF}
   ControlUpdateScrollBars;
 end;
@@ -427,7 +431,7 @@ begin
   ScrollInfo.cbSize := SizeOf(ScrollInfo);
   ScrollInfo.fMask := SIF_UPDATEPOLICY;
   ScrollInfo.nTrackPos := TrackToPolicyMap[FTracking];
-  SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, FVisible);
+  SetScrollInfo(ControlHandle, IntfBarKind[Kind], ScrollInfo, ScrollBarShouldBeVisible);
 end;
 
 function TControlScrollBar.ControlHandle: HWnd;
@@ -470,8 +474,9 @@ end;
 
 function TControlScrollBar.IsScrollBarVisible: Boolean;
 begin
-  Result := (FControl <> nil) and FControl.HandleAllocated and
+  Result:=FVisible;
-            FControl.IsControlVisible and Visible;
+  if Result and HandleAllocated then
+    Result := GetScrollbarVisible(ControlHandle, IntfBarKind[Kind]);
 end;
 
 function TControlScrollBar.ScrollPos: Integer;
@@ -501,14 +506,14 @@ end;
 function TControlScrollBar.ClientSizeWithBar: integer;
 begin
   Result:=ClientSize;
-  if not Visible then
+  if not IsScrollBarVisible then
     dec(Result,GetSize);
 end;
 
 function TControlScrollBar.ClientSizeWithoutBar: integer;
 begin
   Result:=ClientSize;
-  if Visible then
+  if IsScrollBarVisible then
     inc(Result,GetSize);
 end;
 
@@ -528,4 +533,9 @@ begin
     Result:=nil;
 end;
 
+function TControlScrollBar.ScrollBarShouldBeVisible: Boolean;
+begin
+  Result:=FVisible and (FRange>FPage);
+end;
+
 // included by forms.pp

lcl/include/scrollingwincontrol.inc

@@ -110,14 +110,15 @@ end;
 
 function TScrollingWinControl.ComputeScrollbars: Boolean;
 // true if something changed
-// update Page, AutoRange, Visible
+// update Page, AutoRange, IsScrollBarVisible
 
-  procedure UpdateRange(p_Bar: TControlScrollBar);
+  function UpdateRange(p_Bar: TControlScrollBar): Boolean;
   var
     SBSize: Longint;
     OtherScrollbar: TControlScrollBar;
     OldAutoRange: LongInt;
   begin
+    Result:=false;
     OldAutoRange := p_Bar.FAutoRange;
     p_Bar.FAutoRange := 0;
     OtherScrollbar := p_Bar.GetOtherScrollBar;
@@ -139,7 +140,7 @@ var
 begin
   Result := False;
 
-  // page (must be smaller than Range and at least 1)
+  // page (must be smaller than Range but at least 1)
   NewPage := Max(1,Min(VertScrollbar.ClientSize, High(HorzScrollbar.FPage)));
   if NewPage <> HorzScrollbar.FPage then
   begin
@@ -153,8 +154,8 @@ begin
     Result := True;
   end;
   // range
-  UpdateRange(HorzScrollbar);
+  if UpdateRange(HorzScrollbar) then Result:=true;
-  UpdateRange(VertScrollbar);
+  if UpdateRange(VertScrollbar) then Result:=true;
 end;
 
 procedure TScrollingWinControl.UpdateScrollbars;
@@ -168,7 +169,7 @@ begin
   FIsUpdating := True;
   try
     if AutoScroll then
-      ComputeScrollbars; // page, autorange, visible
+      ComputeScrollbars; // page, autorange, IsScrollBarVisible
     FVertScrollbar.UpdateScrollbar;
     FHorzScrollbar.UpdateScrollbar;
   finally
@@ -176,12 +177,6 @@ begin
   end;
 end;
 
-function TScrollingWinControl.HasVisibleScrollbars: boolean;
-begin
-  Result := (VertScrollBar <> nil) and VertScrollBar.Visible and
-            (HorzScrollBar <> nil) and HorzScrollBar.Visible;
-end;
-
 function TScrollingWinControl.StoreScrollBars : Boolean;
 begin
   Result := not AutoScroll;

lcl/include/wincontrol.inc

@@ -7899,11 +7899,17 @@ begin
     finally
       Layout.Free;
     end;
-    
+
+    NewWidth:=0;
+    NewHeight:=0;
     // add the control border around the client area
     CurClientRect := GetClientRect;
-    NewWidth:=Width-CurClientRect.Right+NewClientWidth;
+    if (NewClientWidth>0)
-    NewHeight:=Height-CurClientRect.Bottom+NewClientHeight;
+    or ((NewClientWidth=0) and (csAutoSize0x0 in ControlStyle)) then
+      NewWidth:=Width-CurClientRect.Right+NewClientWidth;
+    if (NewClientHeight>0)
+    or ((NewClientHeight=0) and (csAutoSize0x0 in ControlStyle)) then
+      NewHeight:=Height-CurClientRect.Bottom+NewClientHeight;
     {$IF defined(VerboseAutoSize) or defined(VerboseAllAutoSize)}
     debugln(['TWinControl.CalculatePreferredSize ',DbgSName(Self),
       ' HandleAllocated=',HandleAllocated,
@@ -7915,9 +7921,11 @@ begin
     PreferredWidth:=Max(PreferredWidth,NewWidth);
     PreferredHeight:=Max(PreferredHeight,NewHeight);
   end;
-  if (PreferredWidth>0) then
+  if (PreferredWidth>0)
+  or ((PreferredWidth=0) and (csAutoSize0x0 in ControlStyle)) then
     inc(PreferredWidth,BorderSpacing.InnerBorder*2);
-  if PreferredHeight>0 then
+  if (PreferredHeight>0)
+  or ((PreferredHeight=0) and (csAutoSize0x0 in ControlStyle)) then
     inc(PreferredHeight,BorderSpacing.InnerBorder*2);
   {$IFDEF VerboseAutoSize}
   debugln('TWinControl.CalculatePreferredSize ',DbgSName(Self),