* Made the ScrollBars even more robust

* Fixed ListView Scrollbar slider sizes
* Vastly improved the speed of adding many items at a time to a ListView

3 files changed, 105 insertions, 29 deletions

diff --git a/examples/gui/listviewtest/listviewtest.lpr b/examples/gui/listviewtest/listviewtest.lpr
index 9d503590..a8d64a31 100644
--- a/examples/gui/listviewtest/listviewtest.lpr
+++ b/examples/gui/listviewtest/listviewtest.lpr
@@ -15,6 +15,7 @@ type
     FEdit: TfpgEdit;
     FAddButton: TfpgButton;
     FListView: TfpgListView;
+    FTmpListView: TfpgListView;
     FQuitButton: TfpgButton;
     FCheck: TfpgCheckBox;
     
@@ -22,7 +23,7 @@ type
     procedure AddBttn(Sender: TObject);
     procedure ShowHeadersChange(Sender: TObject);
     procedure PaintItem(ListView: TfpgListView; ACanvas: TfpgCanvas; Item: TfpgLVItem;
-                                   Area:TRect; var PaintPart: TfpgLVItemPaintPart);
+                                   ItemIndex: Integer; Area:TRect; var PaintPart: TfpgLVItemPaintPart);
     
   public
     constructor Create(AOwner: TComponent); override;
@@ -39,16 +40,22 @@ end;
 procedure TMainForm.AddBttn(Sender: TObject);
 var
   Item: TfpgLVItem;
+  I: Integer;
 begin
   FListView.BeginUpdate;
-  Item := FListView.ItemAdd;
-  Item.Caption :=FEdit.Text+IntToStr(FListView.Items.Count);
-  Item.SubItems.Add('0');
-  Item.SubItems.Add('1');
-  Item.SubItems.Add('2');
-  Item.SubItems.Add('3');
-  Item.SubItems.Add('4');
+  FTmpListView.BeginUpdate;
+  FListView.Items.Capacity := FListView.Items.Capacity +1000000;
+  for I := 0 to 999999 do begin
+    Item := FListView.ItemAdd;
+    Item.Caption :=FEdit.Text+IntToStr(FListView.Items.Count);
+    Item.SubItems.Add('0');
+    Item.SubItems.Add('1');
+    Item.SubItems.Add('2');
+    Item.SubItems.Add('3');
+    Item.SubItems.Add('4');
+  end;
   FListView.EndUpdate;
+  FTmpListView.EndUpdate;
 
 end;
 
@@ -58,15 +65,14 @@ begin
 end;
 
 procedure TMainForm.PaintItem(ListView: TfpgListView; ACanvas: TfpgCanvas;
-  Item: TfpgLVItem; Area: TRect; var PaintPart: TfpgLVItemPaintPart);
+  Item: TfpgLVItem; ItemIndex: Integer; Area: TRect; var PaintPart: TfpgLVItemPaintPart);
 begin
-  if ListView.Items.IndexOf(Item) mod 2 = 0 then  ACanvas.TextColor := clRed;;
+  if ItemIndex mod 2 = 0 then  ACanvas.TextColor := clRed;
 end;
 
 constructor TMainForm.Create(AOwner: TComponent);
 var
   LVColumn: TfpgLVColumn;
-  TmpListView : TfpgListView;
 begin
   inherited Create(AOwner);
 
@@ -84,8 +90,8 @@ begin
     MultiSelect := True;
   end;
   
-  TmpListView := TfpgListView.Create(Self);
-  with TmpListView do begin
+  FTmpListView := TfpgListView.Create(Self);
+  with FTmpListView do begin
     Parent := Self;
     Top := 10;
     Left := 335;
@@ -101,7 +107,7 @@ begin
   LVColumn.Width := 150;
   LVColumn.Height := 50;
   FListView.Columns.Add(LVColumn);
-  TmpListView.Columns.Add(LVColumn);
+  FTmpListView.Columns.Add(LVColumn);
   
   LVColumn := TfpgLVColumn.Create(FListView.Columns);
   LVColumn.Caption := 'Column 2';
@@ -109,7 +115,7 @@ begin
   LVColumn.Height := 50;
   //LVColumn.Visible := False;
   FListView.Columns.Add(LVColumn);
-  //TmpListView.Columns.Add(LVColumn);
+  //FTmpListView.Columns.Add(LVColumn);
 
   LVColumn := TfpgLVColumn.Create(FListView.Columns);
   LVColumn.Caption := 'Column 3';
@@ -117,7 +123,7 @@ begin
   LVColumn.Height := 50;
   //LVColumn.Visible := False;
   FListView.Columns.Add(LVColumn);
-  TmpListView.Columns.Add(LVColumn);
+  FTmpListView.Columns.Add(LVColumn);
   LVColumn.ColumnIndex := 2;
 
 
diff --git a/src/gui/gui_listview.pas b/src/gui/gui_listview.pas
index 926538e6..369ce03c 100644
--- a/src/gui/gui_listview.pas
+++ b/src/gui/gui_listview.pas
@@ -67,7 +67,7 @@ type
   TfpgLVItemPaintPart = set of (lvppBackground, lvppIcon, lvppText, lvppFocused);
   
   TfpgLVPaintItemEvent = procedure(ListView: TfpgListView; Canvas: TfpgCanvas; Item: TfpgLVItem;
-                                   Area:TRect; var PaintPart: TfpgLVItemPaintPart) of object;
+                                   ItemIndex: Integer; Area:TRect; var PaintPart: TfpgLVItemPaintPart) of object;
   
   
   IfpgLVItemViewer = interface
@@ -80,10 +80,13 @@ type
 
   TfpgLVItems = class(TObject)
   private
+    FUpdateCount: Integer;
     FColumns: TfpgLVColumns;
     FViewers: TList;
     FItems: TList;
+    function GetCapacity: Integer;
     function    GetItem(AIndex: Integer): TfpgLVItem;
+    procedure SetCapacity(const AValue: Integer);
     procedure   SetItem(AIndex: Integer; const AValue: TfpgLVItem);
     procedure   AddViewer(AValue: IfpgLVItemViewer);
     procedure   DeleteViewer(AValue: IfpgLVItemViewer);
@@ -100,7 +103,10 @@ type
     procedure   Delete(AIndex: Integer);
     function    IndexOf(AItem: TfpgLVItem): Integer;
     procedure   InsertItem(AItem: TfpgLVItem; AIndex: Integer);
+    procedure   BeginUpdate;
+    procedure   EndUpdate;
 
+    property    Capacity: Integer read GetCapacity write SetCapacity;
     property    Columns: TfpgLVColumns read FColumns;
     property    Item[AIndex: Integer]: TfpgLVItem read GetItem write SetItem;
   end;
@@ -110,9 +116,9 @@ type
     FCaption: String;
     FItems: TfpgLVItems;
     FSubItems: TStrings;
-    function GetSelected(ListView: TfpgListView): Boolean;
+    function    GetSelected(ListView: TfpgListView): Boolean;
     procedure   SetCaption(const AValue: String);
-    procedure SetSelected(ListView: TfpgListView; const AValue: Boolean);
+    procedure   SetSelected(ListView: TfpgListView; const AValue: Boolean);
     procedure   SubItemsChanged(Sender: TObject);
   public
     constructor Create(Items: TfpgLVItems); virtual;
@@ -154,6 +160,7 @@ type
     procedure   ItemSetSelected(const AItem: TfpgLVItem; const AValue: Boolean);
     function    ItemGetFromPoint(const X, Y: Integer): TfpgLVItem;
     function    ItemGetRect(AIndex: Integer): TRect;
+    function    ItemIndexFromY(Y: Integer): Integer;
     function    HeaderHeight: Integer;
     procedure   DoRepaint;
   protected
@@ -189,6 +196,16 @@ begin
   Result := TfpgLVItem(FItems.Items[AIndex]);
 end;
 
+function TfpgLVItems.GetCapacity: Integer;
+begin
+  Result := FItems.Capacity;
+end;
+
+procedure TfpgLVItems.SetCapacity(const AValue: Integer);
+begin
+  FItems.Capacity := AValue;
+end;
+
 procedure TfpgLVItems.SetItem(AIndex: Integer; const AValue: TfpgLVItem);
 begin
   FItems.Items[AIndex] := AValue;
@@ -216,6 +233,7 @@ var
   I: Integer;
   AIndex: Integer;
 begin
+  if FUpdateCount > 0 then Exit;
   AIndex := IndexOf(AItem);
   for I := 0 to FViewers.Count -1 do begin
     IfpgLVItemViewer(FViewers.Items[I]).ItemChanged(AIndex);
@@ -227,6 +245,7 @@ var
   I: Integer;
   AIndex: Integer;
 begin
+  if FUpdateCount > 0 then Exit;
   AIndex := IndexOf(AItem);
   for I := 0 to FViewers.Count -1 do begin
     IfpgLVItemViewer(FViewers.Items[I]).ItemAdded(AIndex);
@@ -238,6 +257,7 @@ var
   I: Integer;
   AIndex: Integer;
 begin
+  if FUpdateCount > 0 then Exit;
   AIndex := IndexOf(AItem);
   for I := 0 to FViewers.Count -1 do begin
     IfpgLVItemViewer(FViewers.Items[I]).ItemDeleted(AIndex);
@@ -288,6 +308,18 @@ begin
   else
     raise Exception.Create('Item is not of TfpgLVItem type!');
 end;
+
+procedure TfpgLVItems.BeginUpdate;
+begin
+  Inc(FUpdateCount);
+end;
+
+procedure TfpgLVItems.EndUpdate;
+begin
+  Dec(FUpdateCount);
+  if FUpdateCount < 0 then FUpdateCount := 0;
+end;
+
 { TfpgLVItem }
 
 procedure TfpgLVItem.SetCaption(const AValue: String);
@@ -430,6 +462,18 @@ begin
   if FVScrollBar.Visible then Dec(Result.Right, FVScrollBar.Width);
 end;
 
+function TfpgListView.ItemIndexFromY(Y: Integer): Integer;
+var
+  TopPos: Integer;
+begin
+  if ShowHeaders and (Y < HeaderHeight) then Exit(-1);
+
+  TopPos := (FVScrollBar.Position + Y) - 2;
+  if ShowHeaders then Dec(TopPos, HeaderHeight);
+  Result := TopPos div ItemHeight;
+  if Result > Fitems.Count-1 then Result := -1;
+end;
+
 function TfpgListView.HeaderHeight: Integer;
 begin
   Result := Canvas.Font.Height + 10;
@@ -451,13 +495,25 @@ procedure TfpgListView.HandleLMouseDown(x, y: integer; shiftstate: TShiftState
   );
 var
   Item: TfpgLVItem;
+  MinY, MinX, MaxY, MaxX: Integer;
 begin
   inherited HandleLMouseDown(x, y, shiftstate);
+  
+  MinY := 2; MinX := 2; MaxY := Height -2; MaxX := Width -2;
+  
+  if FVScrollBar.Visible then Dec(MaxX, FVScrollBar.Width);
+  if FHScrollBar.Visible then Dec(MaxY, FHScrollBar.Height);
+  if FShowHeaders then begin
+    // TODO  HeaderClick
+    Inc(MinY, HeaderHeight);
+  end;
+
+  if (X > MaxX) or (X < MinX) or (Y > MaxY) or (Y < MinY) then Exit;
+
   Item := ItemGetFromPoint(X, Y);
   if not FMultiSelect then FSelected.Clear;
   if Item <> nil then begin
-    //WriteLn('Got ITem: ', Item.Caption);
-    FItemIndex := FItems.IndexOf(Item);
+    FItemIndex := ItemIndexFromY(Y);
     if FMultiSelect then begin
       if not ((ssCtrl in shiftstate) or (ssShift in shiftstate)) then begin
         FSelected.Clear;
@@ -527,7 +583,6 @@ end;
 
 procedure TfpgListView.PaintItems;
 var
-  //ItemRect: TfpgRect;
   VisibleItem: TfpgLVItem;
   FirstIndex,
   LastIndex: Integer;
@@ -568,7 +623,7 @@ begin
     Canvas.FillRectangle(ItemRect);
     Exclude(PaintPart, lvppBackground);
     TextColor := Canvas.TextColor;
-    if Assigned(FOnPaintItem) then FOnPaintItem(Self, Canvas, Item, ItemRect, PaintPart);
+    if Assigned(FOnPaintItem) then FOnPaintItem(Self, Canvas, Item, I, ItemRect, PaintPart);
 
     if lvppIcon in PaintPart then begin
       // TODO paint icon
@@ -621,16 +676,13 @@ begin
       Inc(MaxH, Columns.Column[I].Width);
   end;
   
-  MaxV := (FItems.Count+1) * ItemHeight - (Height);
+  MaxV := (FItems.Count+2) * ItemHeight - (Height);
   if ShowHeaders then Inc(MaxV, HeaderHeight);
-
-
   
   if FHScrollBar.Visible then begin
     FHScrollBar.Top := Height - FHScrollBar.Height - (BevelSize );
     FHScrollBar.Left := BevelSize;
     FHScrollBar.Width := Width - (BevelSize * 2);
-    Inc(MaxV, FHScrollBar.Height);
   end;
   
   if FVScrollBar.Visible then begin
@@ -649,6 +701,20 @@ begin
   FHScrollBar.Max := MaxH-(Width-(BevelSize * 2));
   FVScrollBar.Max := MaxV;
   
+  if FVScrollBar.Max = 0 then
+    FVScrollBar.SliderSize := 1
+  else
+    FVScrollBar.SliderSize := FVScrollBar.Height / (FVScrollBar.Max + FVScrollBar.Height);
+  FVScrollBar.RepaintSlider;
+
+  if FHScrollBar.Max = 0 then
+    FHScrollBar.SliderSize := 1
+  else
+    FHScrollBar.SliderSize := FHScrollBar.Width / (FHScrollBar.Max + FHScrollBar.Width);
+  FHScrollBar.RepaintSlider;
+
+
+  
   FHScrollBar.UpdateWindowPosition;
   FVScrollBar.UpdateWindowPosition;
 end;
@@ -687,10 +753,12 @@ end;
 procedure TfpgListView.BeginUpdate;
 begin
   Inc(FUpdateCount);
+  FItems.BeginUpdate;
 end;
 
 procedure TfpgListView.EndUpdate;
 begin
+  FItems.EndUpdate;
   Dec(FUpdateCount);
   if FUpdateCount < 0 then FUpdateCount := 0;
   if FUpdateCount = 0 then DoRePaint;
diff --git a/src/gui/gui_scrollbar.pas b/src/gui/gui_scrollbar.pas
index 56baa257..e95d3a2f 100644
--- a/src/gui/gui_scrollbar.pas
+++ b/src/gui/gui_scrollbar.pas
@@ -125,14 +125,16 @@ end;
 procedure TfpgScrollBar.SetMax(const AValue: integer);
 begin
   if AValue = FMax then Exit;
-  FMax := AValue;
+  if AValue < FMin then FMax := FMin
+  else FMax := AValue;
   if FPosition > FMax then SetPosition(FMax);
 end;
 
 procedure TfpgScrollBar.SetMin(const AValue: integer);
 begin
   if AValue = FMin then Exit;
-  FMin := AValue;
+  if AValue > FMax then FMin := FMax
+  else FMin := AValue;
   if FPosition < FMin then SetPosition(FMin);
 end;