generalabilitiesdemo.pas

来自「本系统前端界面采用WINDOWS 窗口风格」· PAS 代码 · 共 532 行 · 第 1/2 页

unit GeneralAbilitiesDemo;

// Virtual Treeview sample form demonstrating following features:
//   - General use and feel of TVirtualStringTree.
//   - Themed/non-themed painting.
//   - Node button styles.
//   - Selection rectangle styles.
//   - Multiple columns, header, customize column backgrounds, header popup.
//   - Unicode strings.
//   - OLE drag'n drop image.
//   - Switchable main column.
//   - Right click select and drag.
//   - Node specific popup menu.
//   - Save tree content as text file.
// Written by Mike Lischke.

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, Buttons, VirtualTrees, ComCtrls, ExtCtrls, ImgList, Menus,
  StdActns, ActnList, VTHeaderPopup;

type                                        
  TGeneralForm = class(TForm)
    VST2: TVirtualStringTree;
    CheckMarkCombo: TComboBox;
    Label18: TLabel;
    MainColumnUpDown: TUpDown;        
    Label19: TLabel;
    BitBtn1: TBitBtn;
    Label8: TLabel;
    TreeImages: TImageList;
    FontDialog1: TFontDialog;
    PopupMenu1: TPopupMenu;
    Onemenuitem1: TMenuItem;
    forrightclickselection1: TMenuItem;
    withpopupmenu1: TMenuItem;
    RadioGroup1: TRadioGroup;
    RadioGroup2: TRadioGroup;
    VTHPopup: TVTHeaderPopupMenu;
    ThemeRadioGroup: TRadioGroup;
    SaveButton: TBitBtn;
    SaveDialog: TSaveDialog;
    procedure BitBtn1Click(Sender: TObject);
    procedure VST2InitNode(Sender: TBaseVirtualTree; ParentNode, Node: PVirtualNode;
      var InitialStates: TVirtualNodeInitStates);
    procedure VST2InitChildren(Sender: TBaseVirtualTree; Node: PVirtualNode; var ChildCount: Cardinal);
    procedure VST2NewText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; Text: WideString);
    procedure VST2GetImageIndex(Sender: TBaseVirtualTree; Node: PVirtualNode; Kind: TVTImageKind; Column: TColumnIndex;
      var Ghosted: Boolean; var Index: Integer);
    procedure VST2GetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;
      var Text: WideString);
    procedure VST2PaintText(Sender: TBaseVirtualTree; const Canvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex;
      TextType: TVSTTextType);
    procedure VST2GetNodeDataSize(Sender: TBaseVirtualTree; var NodeDataSize: Integer);
    procedure CheckMarkComboChange(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure MainColumnUpDownChanging(Sender: TObject; var AllowChange: Boolean);
    procedure VST2GetPopupMenu(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex; const P: TPoint;
      var AskParent: Boolean; var PopupMenu: TPopupMenu);
    procedure VST2KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure RadioGroup1Click(Sender: TObject);
    procedure VST2FocusChanging(Sender: TBaseVirtualTree; OldNode, NewNode: PVirtualNode; OldColumn,
      NewColumn: TColumnIndex; var Allowed: Boolean);
    procedure RadioGroup2Click(Sender: TObject);
    procedure ThemeRadioGroupClick(Sender: TObject);
    procedure SaveButtonClick(Sender: TObject);
    procedure VST2StateChange(Sender: TBaseVirtualTree; Enter,
      Leave: TVirtualTreeStates);
    procedure VST2DragOver(Sender: TBaseVirtualTree; Source: TObject; Shift: TShiftState; State: TDragState; Pt: TPoint;
      Mode: TDropMode; var Effect: Integer; var Accept: Boolean);
  end;

var
  GeneralForm: TGeneralForm;

//----------------------------------------------------------------------------------------------------------------------

implementation

uses
  ShellAPI, Main, States;

{$R *.DFM}

//----------------------------------------------------------------------------------------------------------------------

type
  PNodeData2 = ^TNodeData2;
  TNodeData2 = record
    Caption,
    StaticText,
    ForeignText: WideString;
    ImageIndex,
    Level: Integer;
  end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.FormCreate(Sender: TObject);

var
  I: Integer;

begin
  // Determine if we are running on Windows XP.
  ThemeRadioGroup.Enabled := (Win32MajorVersion >= 5) and (Win32MinorVersion >= 1);
  if ThemeRadioGroup.Enabled then
    ThemeRadioGroup.ItemIndex := 0;

  CheckMarkCombo.ItemIndex := 3;

  // Add a second line of hint text for column headers (not possible in the object inspector).
  with VST2.Header do
    for I := 0 to Columns.Count - 1 do
      Columns[I].Hint := Columns[I].Hint + #10 + '(Can show further information in hints too.)';

  ConvertToHighColor(TreeImages);
end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.VST2GetNodeDataSize(Sender: TBaseVirtualTree; var NodeDataSize: Integer);

// Returns the size of a node record. Since this size is fixed already at
// creation time it would make sense to avoid this event and assign the value
// in OnCreate of the form (see there for the other trees). But this is a
// demo program, so I want to show this way too. Note the -1 value in
// VST2.NodeDataSize which primarily causes this event to be fired.

begin
  NodeDataSize := SizeOf(TNodeData2);
end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.VST2PaintText(Sender: TBaseVirtualTree; const Canvas: TCanvas; Node: PVirtualNode;
  Column: TColumnIndex; TextType: TVSTTextType);

var
  Data: PNodeData2;

begin
  Data := Sender.GetNodeData(Node);
  case Column of
    0: // main column
      case TextType of
        ttNormal:
          if Data.Level = 0 then
            Canvas.Font.Style := Canvas.Font.Style + [fsBold];
        ttStatic:
          begin
            Canvas.Font.Color := clBlue;
            Canvas.Font.Style := Canvas.Font.Style - [fsBold];
          end;
      end;
    1: // image column (there is no text)
      ;
    2: // language column (no customization)
      ;
  end;
end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.VST2GetText(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex;
  TextType: TVSTTextType; var Text: WideString);

// Returns the text as it is stored in the nodes data record.

var
  Data: PNodeData2;

begin
  Data := Sender.GetNodeData(Node);
  Text := '';
  case Column of
    0: // main column (has two different captions)
      case TextType of
        ttNormal:
          Text := Data.Caption;
        ttStatic:
          Text := Data.StaticText;
      end;
    1: // no text in the image column
      ;
    2:
      if TextType = ttNormal then
        Text := Data.ForeignText;
  end;
end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.VST2InitNode(Sender: TBaseVirtualTree; ParentNode, Node: PVirtualNode;
  var InitialStates: TVirtualNodeInitStates);

const
  LevelToCheckType: array[0..4] of TCheckType = (
    ctButton, ctRadioButton, ctTriStateCheckBox, ctCheckBox, ctNone
  );

var
  Data: PNodeData2;

begin
  Data := Sender.GetNodeData(Node);
  with Data^ do
  begin
    Level := Sender.GetNodeLevel(Node);
    if Level < 4 then
    begin
      Include(InitialStates, ivsHasChildren);
      if Level = 0 then
        Include(InitialStates, ivsExpanded);
    end;

    Caption := Format('Level %d, Index %d', [Level, Node.Index]);
    if Level in [0, 3] then
      StaticText := '(static text)';

    ForeignText := '';
    case Data.Level of
      1:
        begin
          ForeignText := WideChar($2200);
          ForeignText := ForeignText + WideChar($2202) + WideChar($221C) + WideChar($221E) + WideChar($2230) +
            WideChar($2233) + WideChar($2257) + WideChar($225D) + WideChar($22B6) + WideChar($22BF);
        end;
      2:
        begin
          ForeignText := WideChar($32E5);
          ForeignText := ForeignText + WideChar($32E6) + WideChar($32E7) + WideChar($32E8) + WideChar($32E9);
        end;
      3:
        begin
          ForeignText := WideChar($03B1);
          ForeignText := ForeignText + WideChar($03B2) + WideChar($03B3) + WideChar($03B4) + WideChar($03B5) +
            WideChar($03B6) + WideChar($03B7) + WideChar($03B8) + WideChar($03B9);
        end;
      4:
        begin
          ForeignText := WideChar($20AC);
          ForeignText := 'nichts is unm鰃lich ' + ForeignText;
        end;
    end;
    Node.CheckType := LevelToCheckType[Data.Level];
  end;
end;

//----------------------------------------------------------------------------------------------------------------------

procedure TGeneralForm.VST2GetImageIndex(Sender: TBaseVirtualTree; Node: PVirtualNode; Kind: TVTImageKind;
  Column: TColumnIndex; var Ghosted: Boolean; var Index: Integer);

var
  Data: PNodeData2;

begin
  // For this demo only the normal image is shown, you can easily
  // change this for the state and overlay images.
  case Kind of
    ikNormal, ikSelected:
      begin