jvfixededitpopup.pas

East make Tray Icon in delphi

{-----------------------------------------------------------------------------
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL/MPL-1.1.html

Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either expressed or implied. See the License for
the specific language governing rights and limitations under the License.

The Original Code is: JvFixedEditPopUp.PAS, released 2003-03-01.

The Initial Developer of the Original Code is Peter Thornqvist (peter3 at sourceforge dot net)
Portions created by Peter Thornqvist are Copyright (C) 2002 Peter Thornqvist .
All Rights Reserved.

Contributor(s):
Steve Magruder
Remko Bonte

You may retrieve the latest version of this file at the Project JEDI's JVCL home page,
located at http://jvcl.sourceforge.net

Description:
  A unit that can be used to replace the default system popup menu for edit controls. The problem with
  MS implementation is that the Paste command is enabled even when the edit is set to read-only

  By overriding TCustomEdit.GetPopupMenu (virtual), you can return an instance of this popup menu
  instead of the default, i.e:
  interface:

    function GetPopupMenu: TPopupMenu; override;

  implementation:

    function TMyEdit.GetPopupMenu: TPopupMenu;
    begin
      Result := inherited GetPopupMenu;
      if Result = nil then // user has not assigned his own popup menu, so use fixed default
        Result := FixedDefaultEditPopUp(Self);
    end;

  The popup is constructed as a singelton shared between all edit controls using it, so it is
  as resource friendly as we could make it and you should NOT free it after use. The popup is
  not created until first use, so if you don't use it, it doesn't take any resources.

  The popup automatically handles cut, copy, paste, select all, clear and undo events and it's aware
  of and can also handle the ClipboardCommands property in some JVCL edits. Menu items
  are automatically enabled / disabled according to the current state of the edit.

  The popup is "self-translating" based on Windows locale. If you want to
  use resourcestrings and supply your own translations, call FixedDefaultEditPopUseResourceString(True);
  (yes, the name is that long on purpose) *before the first call* to FixedDefaultEditPopUp.

  UPDATE 2003-07-14:
    Rewritten to handle any TWinControl descendant. To make a TWinControl
    component compatible it should implement the following messages and styles:
      * If the control is readonly, it should set ES_READONLY in GWL_STYLE
        (this can be done using the EM_SETREADONLY message for edit descendants)
      * If text can be selected, the control should implement the EM_GETSEL message
      * If the control has undo capability, it should implement the EM_CANUNDO message

    The control should also react to the following messages:
      * Undo: WM_UNDO
      * Cut: WM_CUT
      * Copy: WM_COPY
      * Paste: WM_PASTE
      * Clear: WM_CLEAR
      * Select All: EM_SETSEL with wParam=0 and lParam=-1

History:
3.0:
  2003-09-19:
    - introduced IFixedPopupIntf
    - speed optimation in THiddenPopupObject.GetPopupMenu
-----------------------------------------------------------------------------}
// $Id: JvFixedEditPopUp.pas,v 1.24 2005/02/17 10:20:34 marquardt Exp $

unit JvFixedEditPopUp;

{$I jvcl.inc}

interface

uses
  {$IFDEF UNITVERSIONING}
  JclUnitVersioning,
  {$ENDIF UNITVERSIONING}
  Windows, Messages, SysUtils, Classes, Controls, Menus, TypInfo,
  JvTypes;

type
  { IFixedPopupIntf is implemented by a component that supports the
    FixedPopupMenu. }
  IFixedPopupIntf = interface
    ['{2ECA1438-EFA5-460A-B586-C30C04B85FF3}']
    function CanUndo: Boolean;
    function CanRedo: Boolean; // unused
    function CanCut: Boolean;
    function CanCopy: Boolean;
    function CanPaste: Boolean;
    function CanSelectAll: Boolean;
    function HasSelection: Boolean;
    procedure Undo;
    procedure Redo; // unused
    procedure Cut;
    procedure Copy;
    procedure Paste;
    { Delete() deletes the selected text without storing the content to the
      clipboard. It's enabled/disabled in the same way as Cut. }
    procedure Delete;
    procedure SelectAll;
  end;

// Returns a popup menu with the standard actions associated with edit controls (Undo, Cut, Copy, Paste, Delete, Select All).
// The actions are handled autmatically by sending messages (WM_COPY, WM_CUT etc) to the control
function FixedDefaultEditPopup(AEdit: TWinControl; Update: Boolean = True): TPopupMenu;
// Call with Value set to True to use the internal resourcestrings instead of those
// provided by Windows. These strings can subsequently be translated using the ITE.
// By default, the Windows provided strings are used.
procedure FixedDefaultEditPopUseResourceString(Value: Boolean);

// Updates the menu items enabled property
procedure FixedDefaultEditPopupUpdate(AEdit: TWinControl);

{$IFDEF UNITVERSIONING}
const
  UnitVersioning: TUnitVersionInfo = (
    RCSfile: '$RCSfile: JvFixedEditPopUp.pas,v $';
    Revision: '$Revision: 1.24 $';
    Date: '$Date: 2005/02/17 10:20:34 $';
    LogPath: 'JVCL\run'
  );
{$ENDIF UNITVERSIONING}

implementation

uses
  JvResources;

type
  THiddenPopupObject = class(TComponent)
  private
    FEdit: TWinControl;
    FPopupMenu: TPopupMenu;
    procedure GetDefaultMenuCaptions;
    procedure DoSelectAll(Sender: TObject);
    procedure DoUndo(Sender: TObject);
    procedure DoDelete(Sender: TObject);
    procedure DoPaste(Sender: TObject);
    procedure DoCut(Sender: TObject);
    procedure DoCopy(Sender: TObject);
    function CanUndo: Boolean;
    function ReadOnly: Boolean;
    function GetTextLen: Integer;
    function SelLength: Integer;
    //function GetPopupMenu: TPopupMenu;
    function GetPopupMenuEx(Update: Boolean): TPopupMenu;
    procedure SetEdit(const Value: TWinControl);
    function GetClipboardCommands: TJvClipboardCommands;
    procedure UpdateItems;
  protected
    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
  public
    property Edit: TWinControl read FEdit write SetEdit;
    // property PopupMenu: TPopupMenu read GetPopupMenu;
  end;

var
  GlobalHiddenPopup: THiddenPopupObject = nil;
  GlobalUseResourceStrings: Boolean = False;

function FixedDefaultEditPopup(AEdit: TWinControl; Update: Boolean = True): TPopupMenu;
begin
  if GlobalHiddenPopup = nil then
    GlobalHiddenPopup := THiddenPopupObject.Create(nil);
  GlobalHiddenPopup.Edit := AEdit;
  Result := GlobalHiddenPopup.GetPopupMenuEx(Update);
end;

procedure FixedDefaultEditPopUseResourceString(Value: Boolean);
begin
  GlobalUseResourceStrings := Value;
end;

procedure FixedDefaultEditPopupUpdate(AEdit: TWinControl);
begin
  if (GlobalHiddenPopup <> nil) and (GlobalHiddenPopup.Edit = AEdit) then
    GlobalHiddenPopup.UpdateItems;
end;

//=== { THiddenPopupObject } =================================================

function THiddenPopupObject.CanUndo: Boolean;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    Result := SendMessage(Edit.Handle, EM_CANUNDO, 0, 0) <> 0
  else
    Result := False;
end;

procedure THiddenPopupObject.DoCopy(Sender: TObject);
var
  PopupIntf: IFixedPopupIntf;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    if Edit.GetInterface(IFixedPopupIntf, PopupIntf) then
      PopupIntf.Copy
    else
      Edit.Perform(WM_COPY, 0, 0);
end;

procedure THiddenPopupObject.DoCut(Sender: TObject);
var
  PopupIntf: IFixedPopupIntf;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    if Edit.GetInterface(IFixedPopupIntf, PopupIntf) then
      PopupIntf.Cut
    else
      Edit.Perform(WM_CUT, 0, 0);
end;

procedure THiddenPopupObject.DoDelete(Sender: TObject);
var
  PopupIntf: IFixedPopupIntf;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    if Edit.GetInterface(IFixedPopupIntf, PopupIntf) then
      PopupIntf.Delete
    else
      Edit.Perform(WM_CLEAR, 0, 0);
end;

procedure THiddenPopupObject.DoPaste(Sender: TObject);
var
  PopupIntf: IFixedPopupIntf;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    if Edit.GetInterface(IFixedPopupIntf, PopupIntf) then
      PopupIntf.Paste
    else
      Edit.Perform(WM_PASTE, 0, 0);
end;

procedure THiddenPopupObject.DoSelectAll(Sender: TObject);
var
  PopupIntf: IFixedPopupIntf;
begin
  if Assigned(Edit) and Edit.HandleAllocated then
    if Edit.GetInterface(IFixedPopupIntf, PopupIntf) then
      PopupIntf.SelectAll
    else
      Edit.Perform(EM_SETSEL, 0, -1);
end;