Ingredients needed:
AlphaBlend
for the glassy effect,
GradientFill
for the top gradient ellipse,
MaskBlt
to exclude non-rectangular already drawn parts when drawing,
- indeed some math, pretty easy though.
确实有必要将起草任务分成小步骤,并按正确的顺序排列。 那么,这并不像最初似乎一样不可能。
在以下法典中,我使用三个临时轨道图达到最终目标:
- a memory bitmap on which everything is drawn to reduce flicker,
- a temporary bitmap, needed for assistance,
- a mask bitmap for storage of a clipping shape.
我不喜欢在法典中发表评论,但我期望自己发言:
unit GlassLabel;
interface
uses
Classes, Controls, Windows, Graphics, Math;
const
DefTransparency = 30;
type
TPercentage = 0..100;
TGlassLabel = class(TGraphicControl)
private
FTransparency: TPercentage;
procedure SetTransparency(Value: TPercentage);
protected
procedure Paint; override;
public
constructor Create(AOwner: TComponent); override;
procedure SetBounds(ALeft, ATop, AWidth, AHeight: Integer); override;
published
property Caption;
property Color;
property Font;
property Transparency: TPercentage read FTransparency
write SetTransparency default DefTransparency;
end;
implementation
type
PTriVertex = ^TTriVertex;
TTriVertex = record
X: DWORD;
Y: DWORD;
Red: WORD;
Green: WORD;
Blue: WORD;
Alpha: WORD;
end;
TRGB = record
R: Byte;
G: Byte;
B: Byte;
end;
function GradientFill(DC: HDC; Vertex: PTriVertex; NumVertex: ULONG;
Mesh: Pointer; NumMesh, Mode: ULONG): BOOL; stdcall; overload;
external msimg32 name GradientFill ;
function GradientFill(DC: HDC; const ARect: TRect; StartColor,
EndColor: TColor; Vertical: Boolean): Boolean; overload;
const
Modes: array[Boolean] of ULONG = (GRADIENT_FILL_RECT_H, GRADIENT_FILL_RECT_V);
var
Vertices: array[0..1] of TTriVertex;
GRect: TGradientRect;
begin
Vertices[0].X := ARect.Left;
Vertices[0].Y := ARect.Top;
Vertices[0].Red := GetRValue(ColorToRGB(StartColor)) shl 8;
Vertices[0].Green := GetGValue(ColorToRGB(StartColor)) shl 8;
Vertices[0].Blue := GetBValue(ColorToRGB(StartColor)) shl 8;
Vertices[0].Alpha := 0;
Vertices[1].X := ARect.Right;
Vertices[1].Y := ARect.Bottom;
Vertices[1].Red := GetRValue(ColorToRGB(EndColor)) shl 8;
Vertices[1].Green := GetGValue(ColorToRGB(EndColor)) shl 8;
Vertices[1].Blue := GetBValue(ColorToRGB(EndColor)) shl 8;
Vertices[1].Alpha := 0;
GRect.UpperLeft := 0;
GRect.LowerRight := 1;
Result := GradientFill(DC, @Vertices, 2, @GRect, 1, Modes[Vertical]);
end;
function GetRGB(AColor: TColor): TRGB;
begin
AColor := ColorToRGB(AColor);
Result.R := GetRValue(AColor);
Result.G := GetGValue(AColor);
Result.B := GetBValue(AColor);
end;
function MixColor(Base, MixWith: TColor; Factor: Single): TColor;
var
FBase: TRGB;
FMixWith: TRGB;
begin
if Factor <= 0 then
Result := Base
else if Factor >= 1 then
Result := MixWith
else
begin
FBase := GetRGB(Base);
FMixWith := GetRGB(MixWith);
with FBase do
begin
R := R + Round((FMixWith.R - R) * Factor);
G := G + Round((FMixWith.G - G) * Factor);
B := B + Round((FMixWith.B - B) * Factor);
Result := RGB(R, G, B);
end;
end;
end;
function ColorWhiteness(C: TColor): Single;
begin
Result := (GetRValue(C) + GetGValue(C) + GetBValue(C)) / 255 / 3;
end;
function ColorBlackness(C: TColor): Single;
begin
Result := 1 - ColorWhiteness(C);
end;
{ TGlassLabel }
constructor TGlassLabel.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
ControlStyle := [csOpaque];
FTransparency := DefTransparency;
end;
procedure TGlassLabel.Paint;
const
DSTCOPY = $00AA0029;
DrawTextFlags = DT_CENTER or DT_END_ELLIPSIS or DT_SINGLELINE or DT_VCENTER;
var
W: Integer;
H: Integer;
BorderTop: Integer;
BorderBottom: Integer;
BorderSide: Integer;
Shadow: Integer;
R0: TRect; //Bounds of control
R1: TRect; //Inside border
R2: TRect; //Top gradient
R3: TRect; //Text
R4: TRect; //Perforation
ParentDC: HDC;
Tmp: TBitmap;
Mem: TBitmap;
Msk: TBitmap;
ShadowFactor: Single;
X: Integer;
BlendFunc: TBlendFunction;
procedure PrepareBitmaps;
begin
Tmp.Width := W;
Tmp.Height := H;
Mem.Canvas.Brush.Color := Color;
Mem.Width := W;
Mem.Height := H;
Mem.Canvas.Brush.Style := bsClear;
Msk.Width := W;
Msk.Height := H;
Msk.Monochrome := True;
end;
procedure PrepareMask(R: TRect);
var
Radius: Integer;
begin
Radius := (R.Bottom - R.Top) div 2;
Msk.Canvas.Brush.Color := clBlack;
Msk.Canvas.FillRect(R0);
Msk.Canvas.Brush.Color := clWhite;
Msk.Canvas.Ellipse(R.Left, R.Top, R.Left + 2 * Radius, R.Bottom);
Msk.Canvas.Ellipse(R.Right - 2 * Radius, R.Top, R.Right, R.Bottom);
Msk.Canvas.FillRect(Rect(R.Left + Radius, R.Top, R.Right - Radius,
R.Bottom));
end;
procedure DrawTopGradientEllipse;
begin
GradientFill(Tmp.Canvas.Handle, R2, MixColor(Color, clWhite, 1.0),
MixColor(Color, clWhite, 0.2), True);
PrepareMask(R2);
MaskBlt(Mem.Canvas.Handle, 0, 0, W, H, Tmp.Canvas.Handle, 0, 0,
Msk.Handle, 0, 0, MakeROP4(SRCCOPY, DSTCOPY));
end;
procedure DrawPerforation;
begin
while R4.Right < (W - H div 2) do
begin
Mem.Canvas.Pen.Color := MixColor(Color, clBlack, 0.9);
Mem.Canvas.RoundRect(R4.Left, R4.Top, R4.Right, R4.Bottom, H div 7,
H div 7);
Mem.Canvas.Pen.Color := MixColor(Color, clBlack, 0.5);
Mem.Canvas.RoundRect(R4.Left + 1, R4.Top + 1, R4.Right - 1,
R4.Bottom - 1, H div 7 - 1, H div 7 - 1);
Mem.Canvas.Pen.Color := MixColor(Color, clWhite, 0.33);
Mem.Canvas.MoveTo(R4.Left + H div 14, R4.Top + 1);
Mem.Canvas.LineTo(R4.Right - H div 14, R4.Top + 1);
OffsetRect(R4, R4.Right - R4.Left + H div 12, 0);
end;
end;
procedure DrawCaption;
begin
Mem.Canvas.Font := Font;
ShadowFactor := 0.6 + 0.4 * (Min(1.0, ColorBlackness(Font.Color) + 0.3));
Mem.Canvas.Font.Color := MixColor(Font.Color, clBlack, ShadowFactor);
DrawText(Mem.Canvas.Handle, PChar(Caption), -1, R3, DrawTextFlags);
OffsetRect(R3, -Shadow, Shadow);
Mem.Canvas.Font.Color := Font.Color;
DrawText(Mem.Canvas.Handle, PChar(Caption), -1, R3, DrawTextFlags);
end;
procedure DrawBorderAlias;
begin
Mem.Canvas.Pen.Color := MixColor(Color, clBlack, 0.65);
X := R1.Left + (R1.Bottom - R1.Top) div 2 + 2;
Mem.Canvas.Arc(R1.Left + 1, R1.Top, R1.Left + R1.Bottom - R1.Top + 1,
R1.Bottom, X, 0, X, H);
X := R1.Right - (R1.Bottom - R1.Top) div 2 - 2;
Mem.Canvas.Arc(R1.Right - 1, R1.Top, R1.Right - R1.Bottom + R1.Top - 1,
R1.Bottom, X, H, X, 0);
end;
procedure DrawBorder;
begin
PrepareMask(R1);
Tmp.Canvas.Brush.Color := clWhite;
Tmp.Canvas.Draw(0, 0, Msk);
BitBlt(Mem.Canvas.Handle, 0, 0, W, H, Tmp.Canvas.Handle, 0, 0, SRCAND);
end;
procedure DrawCombineParent;
begin
BitBlt(Tmp.Canvas.Handle, 0, 0, W, H, ParentDC, Left, Top, SRCCOPY);
BlendFunc.BlendOp := AC_SRC_OVER;
BlendFunc.BlendFlags := 0;
BlendFunc.SourceConstantAlpha := Round(FTransparency * High(Byte) / 100);
BlendFunc.AlphaFormat := 0;
AlphaBlend(Mem.Canvas.Handle, 0, 0, W, H, Tmp.Canvas.Handle, 0, 0, W, H,
BlendFunc);
PrepareMask(R0);
MaskBlt(Mem.Canvas.Handle, 0, 0, W, H, Tmp.Canvas.Handle, 0, 0,
Msk.Handle, 0, 0, MakeROP4(DSTCOPY, SRCCOPY));
end;
begin
if HasParent and (Height > 1) then
begin
W := Width;
H := Height;
BorderTop := Max(1, H div 30);
BorderBottom := Max(2, H div 10);
BorderSide := (BorderTop + BorderBottom) div 2;
Shadow := Font.Size div 8;
R0 := ClientRect;
R1 := Rect(BorderSide, BorderTop, W - BorderSide, H - BorderBottom);
R2 := Rect(R1.Left + BorderSide + 1, R1.Top, R1.Right - BorderSide - 1,
R1.Top + H div 4);
R3 := Rect(H div 2 + 1 + Shadow, R1.Top + 1, W - H div 2 - 1,
R1.Bottom - Shadow);
R4 := Bounds(H div 2, R1.Bottom - H div 4 + 1, H div 5, H div 4 - 2);
ParentDC := GetDC(Parent.Handle);
Tmp := TBitmap.Create;
Mem := TBitmap.Create;
Msk := TBitmap.Create;
try
PrepareBitmaps;
DrawTopGradientEllipse;
DrawPerforation;
DrawCaption;
DrawBorderAlias;
DrawBorder;
DrawCombineParent;
BitBlt(Canvas.Handle, 0, 0, W, H, Mem.Canvas.Handle, 0, 0, SRCCOPY);
finally
Msk.Free;
Mem.Free;
Tmp.Free;
ReleaseDC(Parent.Handle, ParentDC);
end;
end;
end;
procedure TGlassLabel.SetBounds(ALeft, ATop, AWidth, AHeight: Integer);
begin
if AWidth < AHeight then
AWidth := AHeight;
inherited SetBounds(ALeft, ATop, AWidth, AHeight);
end;
procedure TGlassLabel.SetTransparency(Value: TPercentage);
begin
if FTransparency <> Value then
begin
FTransparency := Value;
Invalidate;
end;
end;
end.
生产上述产品的样本代码(TImage
, 背景控制):
procedure TForm1.FormCreate(Sender: TObject);
begin
Font.Size := 16;
Font.Color := $00A5781B;
Font.Name := Calibri ;
Font.Style := [fsBold];
with TGlassLabel.Create(Self) do
begin
SetBounds(40, 40, 550, 60);
Color := $00271907;
Caption := 395 Days, 22 Hours, 0 Minutes, 54 Seconds ;
Parent := Self;
end;
with TGlassLabel.Create(Self) do
begin
SetBounds(40, 40 + 119, 550, 60);
Color := $00000097;
Caption := 0 Days, 1 Hours, 59 Minutes, 31 Seconds ;
Parent := Self;
end;
end;
like。