tflatlistboxunit.pas

FlatStyle 一组平面控件

    if Value then
      Include(FSelected, Index)
    else
      Exclude(FSelected, Index)
  else
    begin
      FSelected := FSelected - [0..High(Byte)];
      if Value then
        Include(FSelected, Index)
      else
        Exclude(FSelected, Index);
    end;
  Invalidate;
end;

function TFlatListBox.GetSelCount: Integer;
var
  counter: Integer;
begin
  if MultiSelect then
    begin
      Result := 0;
      for counter := 0 to High(Byte) do
        if counter in FSelected then
          Inc(Result);
    end
  else
    Result := -1;
end;

procedure TFlatListBox.SetScrollBars (Value: Boolean);
begin
  if FScrollBars <> Value then
  begin
    FScrollBars := Value;
    if not (csLoading in ComponentState) then
      if Value then
        Height := Height + 20
      else
        Height := Height - 20;
    SetItemsRect;
  end;
end;

procedure TFlatListBox.DrawScrollBar (canvas: TCanvas);
var
  x, y: Integer;
begin
  // Draw the ScrollBar background
  canvas.Brush.Color := Color;
  canvas.FillRect(Rect(ClientRect.Left, ClientRect.Top, ClientRect.Right, ClientRect.Top + 11));
  canvas.FillRect(Rect(ClientRect.Left, ClientRect.Bottom - 11, ClientRect.Right, ClientRect.Bottom));

  // Draw the ScrollBar border
  canvas.Brush.Color := FBorderColor;
  canvas.FrameRect(Rect(ClientRect.Left, ClientRect.Top, ClientRect.Right, ClientRect.Top + 11));
  canvas.FrameRect(Rect(ClientRect.Left, ClientRect.Bottom - 11, ClientRect.Right, ClientRect.Bottom));

  // Draw the up arrow
  x := (ClientRect.Right - ClientRect.Left) div 2 - 6;
  y := ClientRect.Top + 4;

  if (firstItem <> 0) and Enabled then
  begin
    canvas.Brush.Color := FArrowColor;
    canvas.Pen.Color := FArrowColor;
    canvas.Polygon([Point(x + 4, y + 2), Point(x + 8, y + 2), Point(x + 6, y)]);
  end
  else
  begin
    canvas.Brush.Color := clWhite;
    canvas.Pen.Color := clWhite;
    Inc(x); Inc(y);
    canvas.Polygon([Point(x + 4, y + 2), Point(x + 8, y + 2), Point(x + 6, y)]);
    Dec(x); Dec(y);
    canvas.Brush.Color := clGray;
    canvas.Pen.Color := clGray;
    canvas.Polygon([Point(x + 4, y + 2), Point(x + 8, y + 2), Point(x + 6, y)]);
  end;

  // Draw the down arrow
  y := ClientRect.Bottom - 7;
  if (firstItem + maxItems + 1 <= FItems.Count) and Enabled then
  begin
    canvas.Brush.Color := FArrowColor;
    canvas.Pen.Color := FArrowColor;
    canvas.Polygon([Point(X + 4, Y), Point(X + 8, Y), Point(X + 6, Y + 2)]);
  end
  else
  begin
    canvas.Brush.Color := clWhite;
    canvas.Pen.Color := clWhite;
    Inc(x); Inc(y);
    canvas.Polygon([Point(X + 4, Y), Point(X + 8, Y), Point(X + 6, Y + 2)]);
    Dec(x); Dec(y);
    canvas.Brush.Color := clGray;
    canvas.Pen.Color := clGray;
    canvas.Polygon([Point(X + 4, Y), Point(X + 8, Y), Point(X + 6, Y + 2)]);
  end;
end;

procedure TFlatListBox.Paint;
var
  memoryBitmap: TBitmap;
  counterRect, counterItem: Integer;
  itemRect: ^TRect;
begin
  // create memory-bitmap to draw flicker-free
  memoryBitmap := TBitmap.Create;
  try
    memoryBitmap.Height := ClientRect.Bottom;
    memoryBitmap.Width := ClientRect.Right;
    memoryBitmap.Canvas.Font.Assign(Self.Font);

    // Clear Background
    memoryBitmap.canvas.Brush.Color := FItemsRectColor;
    memoryBitmap.canvas.FillRect(ClientRect);

    // Draw Border
    memoryBitmap.canvas.Brush.Color := FBorderColor;
    memoryBitmap.canvas.FrameRect(ClientRect);

    // Draw ScrollBars
    if ScrollBars then
      DrawScrollBar(memoryBitmap.canvas);

    // Initialize the counter for the Items
    counterItem := firstItem;

    // Draw Items
    for counterRect := 0 to maxItems - 1 do
    begin
      itemRect := FItemsRect.Items[counterRect];
      if (counterItem <= FItems.Count - 1) then
      begin
        // Item is selected
        if counterItem in FSelected then
        begin
          // Fill ItemRect
          memoryBitmap.canvas.brush.color := FItemsSelectColor;
          memoryBitmap.canvas.FillRect(itemRect^);
          // Draw ItemBorder
          memoryBitmap.canvas.brush.color := FBorderColor;
          memoryBitmap.canvas.FrameRect(itemRect^);
        end;
        // Draw ItemText
        memoryBitmap.canvas.brush.style := bsClear;
        InflateRect(itemRect^, -3, 0);
        if Enabled then
          DrawText(memoryBitmap.canvas.Handle, PChar(FItems[counterItem]), Length(FItems[counterItem]), itemRect^, DT_LEFT or DT_VCENTER or DT_SINGLELINE or DT_NOPREFIX)
        else
          begin
            OffsetRect(itemRect^, 1, 1);
            memoryBitmap.canvas.Font.Color := clBtnHighlight;
            DrawText(memoryBitmap.canvas.Handle, PChar(FItems[counterItem]), Length(FItems[counterItem]), itemRect^, DT_LEFT or DT_VCENTER or DT_SINGLELINE or DT_NOPREFIX);
            OffsetRect(itemRect^, -1, -1);
            memoryBitmap.canvas.Font.Color := clBtnShadow;
            DrawText(memoryBitmap.canvas.Handle, PChar(FItems[counterItem]), Length(FItems[counterItem]), itemRect^, DT_LEFT or DT_VCENTER or DT_SINGLELINE or DT_NOPREFIX);
          end;
        InflateRect(itemRect^, 3, 0);
        Inc(counterItem);
      end;
    end;
    // Copy bitmap to screen
    canvas.CopyRect(ClientRect, memoryBitmap.canvas, ClientRect);
  finally
    // delete the memory bitmap
    memoryBitmap.free;
  end;
end;

procedure TFlatListBox.MouseDown (Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
  cursorPos: TPoint;
  counterRect: Integer;
  currentRect: ^TRect;
begin
  GetCursorPos(cursorPos);
  cursorPos := ScreenToClient(cursorPos);

  if (FItems.Count > 0) and (Button = mbLeft) then
  begin
    for counterRect := 0 to FItemsRect.Count - 1 do
    begin
      currentRect := FItemsRect.Items[counterRect];
      if PtInRect(currentRect^, cursorPos) then
      begin
        if MultiSelect then    
          if (firstItem + counterRect) in FSelected then
            Exclude(FSelected, firstItem + counterRect)
          else
            Include(FSelected, firstItem + counterRect)
        else
          begin
            FSelected := FSelected - [0..High(Byte)];
            Include(FSelected, firstItem + counterRect);
          end;
        SetFocus;
        Invalidate;
        Exit;
      end;
    end;
  end;

  if ScrollBars then
  begin
    if PtInRect(Rect(ClientRect.Left, ClientRect.Top, ClientRect.Right, ClientRect.Top + 11), cursorPos) then
    begin
      if (firstItem - 1) < 0 then
        firstItem := 0
      else
        Dec(firstItem);
      SetFocus;
      Invalidate;
      scrollType := up;
      if ScrollTimer.Enabled then
        ScrollTimer.Enabled := False;
      ScrollTimer.OnTimer := ScrollTimerHandler;
      ScrollTimer.Enabled := True;
    end;
    if PtInRect(Rect(ClientRect.Left, ClientRect.Bottom - 11, ClientRect.Right, ClientRect.Bottom), cursorPos) then
    begin
      if firstItem + maxItems + 1 <= FItems.Count then
        Inc(firstItem);
      SetFocus;
      Invalidate;
      scrollType := down;
      if ScrollTimer.Enabled then
        ScrollTimer.Enabled := False;
      ScrollTimer.OnTimer := ScrollTimerHandler;
      ScrollTimer.Enabled := True;
    end;
  end;
  Inherited;
end;

procedure TFlatListBox.MouseUp (Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  ScrollTimer.Enabled := False;
  ScrollTimer.Interval := FTimerInterval;
  inherited MouseUp(Button, Shift, X, Y);
end;

procedure TFlatListBox.ScrollTimerHandler (Sender: TObject);
begin
  ScrollTimer.Interval := FScrollSpeed;
  if scrollType = up then
    if (firstItem - 1) < 0 then
    begin
      firstItem := 0;
      ScrollTimer.Enabled := False;
    end
    else
      Dec(firstItem)
  else
    if firstItem + maxItems + 1 <= FItems.Count then
      Inc(firstItem)
    else
      ScrollTimer.Enabled := False;
  Invalidate;
end;

procedure TFlatListBox.Loaded;
begin
  inherited;
  SetItemsRect;
end;

procedure TFlatListBox.WMSize (var Message: TWMSize);
begin
  inherited;
  // Calculate the maximum items to draw
  if ScrollBars then
    maxItems := (Height - 24) div (FItemsHeight + 2)
  else
    maxItems := (Height - 4) div (FItemsHeight + 2);

  // Set the new Bounds
  if ScrollBars then
    SetBounds(Left, Top, Width, maxItems * (FItemsHeight + 2) + 24)
  else
    SetBounds(Left, Top, Width, maxItems * (FItemsHeight + 2) + 4);

  // Recalculate the itemRects
  SetItemsRect;
end;

procedure TFlatListBox.CMEnabledChanged (var Message: TMessage);
begin
  inherited;
  Invalidate;
end;

procedure TFlatListBox.CMSysColorChange (var Message: TMessage);
begin
  if FUseAdvColors then
  begin
    ParentColor := True;
    CalcAdvColors;
  end;
  Invalidate;
end;

procedure TFlatListBox.CMParentColorChanged (var Message: TWMNoParams);
begin
  inherited;
  if FUseAdvColors then
  begin
    ParentColor := True;
    CalcAdvColors;
  end;
  Invalidate;
end;

end.