SizeGrip, Version 1.2 (alt)
Hinweis: dies ist nicht die neueste Version!
Datei: SizeGrip.pas
{ SizeGrip.pas Delphi component to add a size grip (like if you use a status bar) to the lower right corner of any TWinControl (like TForm). "SizeGripThemed.pas" is the themed version using the currently selected visual style. See the included README.txt for more information and how to use it. Version 1.2 - always find the most current version at http://flocke.vssd.de/prog/code/pascal/sizegrip/ Copyright (C) 2005 Volker Siebert <flocke@vssd.de> All rights reserved. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. } unit SizeGrip; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls; type TSizeGripStyle = ( sgsClassic, sgsWinXP ); TSizeGrip = class(TComponent) private FTargetControl: TWinControl; // Target control FEnabled: boolean; // Size grip enabled? FStyle: TSizeGripStyle; // Display style? FSizeGripRect: TRect; // Current size grip rectangle FOldWndProc: TWndMethod; // Hooked window procedure procedure AttachControl; procedure DetachControl; procedure SetTargetControl(const Value: TWinControl); procedure SetEnabled(const Value: boolean); procedure SetNewStyle(const Value: TSizeGripStyle); protected procedure Notification(AComponent: TComponent; Operation: TOperation); override; procedure GetGripRect(var Rect: TRect); virtual; procedure PaintIt(DC: HDC; const Rect: TRect); virtual; procedure NewWndProc(var Msg: TMessage); virtual; procedure InvalidateGrip; procedure UpdateGrip; public constructor Create(AOwner: TComponent); override; destructor Destroy; override; published property Enabled: boolean read FEnabled write SetEnabled default true; property TargetControl: TWinControl read FTargetControl write SetTargetControl; property Style: TSizeGripStyle read FStyle write SetNewStyle default sgsClassic; end; TSizeGripXP = class(TSizeGrip) public constructor Create(AOwner: TComponent); override; published property Style default sgsWinXP; end; procedure Register; implementation type TWinControlAccess = class(TWinControl); const CEmptyRect: TRect = ( Left: 0; Top: 0; Right: 0; Bottom: 0; ); { TSizeGrip } constructor TSizeGrip.Create(AOwner: TComponent); begin inherited; FEnabled := true; FStyle := sgsClassic; if AOwner.ComponentState * [csLoading, csReading] = [] then begin // Automatically take the owner as the target control if AOwner is TWinControl then TargetControl := TWinControl(AOwner) else if AOwner is TControl then TargetControl := TControl(AOwner).Parent; end; end; destructor TSizeGrip.Destroy; begin TargetControl := nil; inherited; end; procedure TSizeGrip.Notification(AComponent: TComponent; Operation: TOperation); begin inherited; if Operation = opRemove then if AComponent = FTargetControl then TargetControl := nil; end; { Invalidate the current grip rectangle } procedure TSizeGrip.InvalidateGrip; begin if (FTargetControl <> nil) and (FSizeGripRect.Right > FSizeGripRect.Left) and (FSizeGripRect.Bottom > FSizeGripRect.Top) then if FTargetControl.HandleAllocated then InvalidateRect(FTargetControl.Handle, @FSizeGripRect, TRUE); end; { Update (and invalidate) the current grip rectangle } procedure TSizeGrip.UpdateGrip; begin GetGripRect(FSizeGripRect); InvalidateGrip; end; { Attach to FTargetControl: subclass to catch WM_SIZE, WM_ERASEBKGND and WM_NCHITTEST. } procedure TSizeGrip.AttachControl; begin if @FOldWndProc = nil then if ([csDesigning, csDestroying] * ComponentState = []) and (FTargetControl <> nil) and FEnabled and ([csDesigning, csDestroying] * FTargetControl.ComponentState = []) then begin FOldWndProc := FTargetControl.WindowProc; FTargetControl.WindowProc := NewWndProc; UpdateGrip; end; end; { Detach from FTargetControl: remove subclassing. } procedure TSizeGrip.DetachControl; begin if @FOldWndProc <> nil then begin FTargetControl.WindowProc := FOldWndProc; FOldWndProc := nil; InvalidateGrip; FSizeGripRect := CEmptyRect; end; end; { Set the target control } procedure TSizeGrip.SetTargetControl(const Value: TWinControl); begin if Value <> FTargetControl then begin if FTargetControl <> nil then FTargetControl.RemoveFreeNotification(Self); DetachControl; FTargetControl := Value; AttachControl; if FTargetControl <> nil then FTargetControl.FreeNotification(Self); end; end; { Toggle enabled / disabled flag } procedure TSizeGrip.SetEnabled(const Value: boolean); begin if FEnabled <> Value then begin DetachControl; FEnabled := Value; AttachControl; end; end; { Toggle new style flag } procedure TSizeGrip.SetNewStyle(const Value: TSizeGripStyle); begin if FStyle <> Value then begin FStyle := Value; InvalidateGrip; end; end; { The new Window procedure for the attached target control. } procedure TSizeGrip.NewWndProc(var Msg: TMessage); var pt: TPoint; dc: HDC; begin if (not Assigned(FOldWndProc)) or (FTargetControl = nil) then exit; case Msg.Msg of WM_PAINT: begin FOldWndProc(Msg); if TWMPaint(Msg).DC = 0 then begin dc := GetDC(FTargetControl.Handle); try PaintIt(dc, FSizeGripRect); finally ReleaseDC(FTargetControl.Handle, dc); end; end end; WM_NCHITTEST: begin with TWMNcHitTest(Msg) do pt := FTargetControl.ScreenToClient(Point(XPos, YPos)); if PtInRect(FSizeGripRect, pt) then Msg.Result := HTBOTTOMRIGHT else FOldWndProc(TMessage(Msg)); end; WM_SIZE: begin InvalidateGrip; FOldWndProc(Msg); UpdateGrip; end; else FOldWndProc(Msg); end; end; { Calculate the size grip's rectangle } procedure TSizeGrip.GetGripRect(var Rect: TRect); begin if FTargetControl <> nil then begin Rect := FTargetControl.ClientRect; Rect.Left := Rect.Right - 15; Rect.Top := Rect.Bottom - 15; end else Rect := CEmptyRect; end; { Paint the size grip } procedure TSizeGrip.PaintIt(DC: HDC; const Rect: TRect); const StartX = 4; StartY = 4; var ch, cm, cs: COLORREF; procedure Paint3(clr: COLORREF; delta: integer); var pen, oldpen: HPen; begin pen := CreatePen(PS_SOLID, 0, clr); try oldpen := SelectObject(DC, pen); try MoveToEx(DC, Rect.Right - delta, Rect.Bottom - 1, nil); LineTo(DC, Rect.Right, Rect.Bottom - 1 - delta); inc(delta, 4); MoveToEx(DC, Rect.Right - delta, Rect.Bottom - 1, nil); LineTo(DC, Rect.Right, Rect.Bottom - 1 - delta); inc(delta, 4); MoveToEx(DC, Rect.Right - delta, Rect.Bottom - 1, nil); LineTo(DC, Rect.Right, Rect.Bottom - 1 - delta); finally SelectObject(DC, oldpen); end; finally DeleteObject(pen); end; end; procedure PaintBox(x, y: integer); begin SetPixel(DC, x, y, cs); SetPixel(DC, x + 1, y, cs); SetPixel(DC, x, y + 1, cs); SetPixel(DC, x + 1, y + 1, cm); SetPixel(DC, x + 2, y + 1, ch); SetPixel(DC, x + 1, y + 2, ch); SetPixel(DC, x + 2, y + 2, ch); end; function MixColors(c1, c2: COLORREF): COLORREF; begin Result := RGB((GetRValue(c1) + GetRValue(c2)) div 2, (GetGValue(c1) + GetGValue(c2)) div 2, (GetBValue(c1) + GetBValue(c2)) div 2); end; begin ch := ColorToRgb(clBtnHighlight); cs := ColorToRgb(clBtnShadow); // Original look is cm := cs! cm := MixColors(ColorToRgb(TWinControlAccess(FTargetControl).Color), cs); case FStyle of sgsWinXP: begin PaintBox(Rect.Right - StartX, Rect.Bottom - StartY - 8); PaintBox(Rect.Right - StartX - 4, Rect.Bottom - StartY - 4); PaintBox(Rect.Right - StartX, Rect.Bottom - StartY - 4); PaintBox(Rect.Right - StartX - 8, Rect.Bottom - StartY); PaintBox(Rect.Right - StartX - 4, Rect.Bottom - StartY); PaintBox(Rect.Right - StartX, Rect.Bottom - StartY); end; else begin Paint3(cs, 2); Paint3(cm, 3); Paint3(ch, 4); end; end; end; { TSizeGripXP } constructor TSizeGripXP.Create(AOwner: TComponent); begin inherited; FStyle := sgsWinXP; end; { Register } procedure Register; begin RegisterComponents('System', [TSizeGrip, TSizeGripXP]); end; end. |