unit Editors;
{$MODE Delphi}
// Utility unit for the advanced Virtual Treeview demo application which contains the implementation of edit link
// interfaces used in other samples of the demo.
interface
uses
LCLIntf, delphicompat, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, VirtualTrees, ExtDlgs, Buttons, ExtCtrls, ComCtrls,
MaskEdit, LCLType;
type
// Describes the type of value a property tree node stores in its data property.
TValueType = (
vtNone,
vtString,
vtPickString,
vtNumber,
vtPickNumber,
vtMemo,
vtDate
);
//----------------------------------------------------------------------------------------------------------------------
//todo
TDateTimePicker = TComboBox;
type
// Node data record for the the document properties treeview.
PPropertyData = ^TPropertyData;
TPropertyData = record
ValueType: TValueType;
Value: UTF8String; // This value can actually be a date or a number too.
Changed: Boolean;
end;
// Our own edit link to implement several different node editors.
TPropertyEditLink = class(TInterfacedObject, IVTEditLink)
private
FEdit: TWinControl; // One of the property editor classes.
FTree: TVirtualStringTree; // A back reference to the tree calling.
FNode: PVirtualNode; // The node being edited.
FColumn: Integer; // The column of the node being edited.
protected
procedure EditKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
public
destructor Destroy; override;
function BeginEdit: Boolean; stdcall;
function CancelEdit: Boolean; stdcall;
function EndEdit: Boolean; stdcall;
function GetBounds: TRect; stdcall;
function PrepareEdit(Tree: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex): Boolean; stdcall;
procedure ProcessMessage(var Message: TMessage); stdcall;
procedure SetBounds(R: TRect); stdcall;
end;
//----------------------------------------------------------------------------------------------------------------------
type
TPropertyTextKind = (
ptkText,
ptkHint
);
// The following constants provide the property tree with default data.
const
// Types of editors to use for a certain node in VST3.
ValueTypes: array[0..1, 0..12] of TValueType = (
(
vtString, // Title
vtString, // Theme
vtPickString, // Category
vtMemo, // Keywords
vtNone, // Template
vtNone, // Page count
vtNone, // Word count
vtNone, // Character count
vtNone, // Lines
vtNone, // Paragraphs
vtNone, // Scaled
vtNone, // Links to update
vtMemo), // Comments
(
vtString, // Author
vtNone, // Most recently saved by
vtNumber, // Revision number
vtPickString, // Primary application
vtString, // Company name
vtNone, // Creation date
vtDate, // Most recently saved at
vtNone, // Last print
vtNone,
vtNone,
vtNone,
vtNone,
vtNone)
);
// types of editors to use for a certain node in VST3
DefaultValue: array[0..1, 0..12] of String = (
(
'Virtual Treeview', // Title
'native Delphi controls', // Theme
'Virtual Controls', // Category
'virtual, treeview, VCL', // Keywords
'no template used', // Template
'> 900', // Page count
'?', // Word count
'~ 1.000.000', // Character count
'~ 28.000', // Lines
'', // Paragraphs
'False', // Scaled
'www.delphi-gems.com', // Links to update
'Virtual Treeview is much more than a simple treeview.'), // Comments
(
'Dipl. Ing. Mike Lischke', // Author
'Mike Lischke', // Most recently saved by
'3.0', // Revision number
'Delphi', // Primary application
'', // Company name
'July 1999', // Creation date
'January 2002', // Most recently saved at
'', // Last print
'',
'',
'',
'',
'')
);
// Fixed strings for property tree (VST3).
PropertyTexts: array[0..1, 0..12, TPropertyTextKind] of string = (
(// first (upper) subtree
('Title', 'Title of the file or document'),
('Theme', 'Theme of the file or document'),
('Category', 'Category of theme'),
('Keywords', 'List of keywords which describe the content of the file'),
('Template', 'Name of the template which was used to create the document'),
('Page count', 'Number of pages in the document'),
('Word count', 'Number of words in the document'),
('Character count', 'Number of characters in the document'),
('Lines', 'Number of lines in the document'),
('Paragraphs', 'Number of paragraphs in the document'),
('Scaled', 'Scaling of the document for output'),
('Links to update', 'Links which must be updated'),
('Comments', 'Description or comments for the file')
),
(// second (lower) subtree
('Author', 'name of the author of the file or document'),
('Most recently saved by', 'Name of the person who has saved the document last'),
('Revision number', 'Revision number of the file or document'),
('Primary application', 'Name of the application which is primarily used to create this kind of file'),
('Company name', 'Name of the company or institution'),
('Creation date', 'Date when the file or document was created'),
('Most recently saved at', 'Date when the file or document was saved the last time'),
('Last print', 'Date when the file or document was printed the last time'),
('', ''), // the remaining 5 entries are not used
('', ''),
('', ''),
('', ''),
('', '')
)
);
//----------------------------------------------------------------------------------------------------------------------
type
PGridData = ^TGridData;
TGridData = record
ValueType: array[0..3] of TValueType; // one for each column
Value: array[0..3] of Variant;
Changed: Boolean;
end;
// Our own edit link to implement several different node editors.
TGridEditLink = class(TPropertyEditLink, IVTEditLink)
public
function EndEdit: Boolean; stdcall;
function PrepareEdit(Tree: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex): Boolean; stdcall;
end;
//----------------------------------------------------------------------------------------------------------------------
implementation
uses
PropertiesDemo, GridDemo;
//----------------- TPropertyEditLink ----------------------------------------------------------------------------------
// This implementation is used in VST3 to make a connection beween the tree
// and the actual edit window which might be a simple edit, a combobox
// or a memo etc.
destructor TPropertyEditLink.Destroy;
begin
FEdit.Free;
inherited;
end;
//----------------------------------------------------------------------------------------------------------------------
procedure TPropertyEditLink.EditKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
var
CanAdvance: Boolean;
begin
CanAdvance := true;
case Key of
VK_ESCAPE:
if CanAdvance then
begin
FTree.CancelEditNode;
Key := 0;
end;
VK_RETURN:
if CanAdvance then
begin
FTree.EndEditNode;
Key := 0;
end;
VK_UP,
VK_DOWN:
begin
// Consider special cases before finishing edit mode.
CanAdvance := Shift = [];
if FEdit is TComboBox then
CanAdvance := CanAdvance and not TComboBox(FEdit).DroppedDown;
if FEdit is TDateTimePicker then
CanAdvance := CanAdvance and not TDateTimePicker(FEdit).DroppedDown;
if CanAdvance then
begin
// Forward the keypress to the tree. It will asynchronously change the focused node.
PostMessage(FTree.Handle, WM_KEYDOWN, Key, 0);
Key := 0;
end;
end;
end;
end;
//----------------------------------------------------------------------------------------------------------------------
function TPropertyEditLink.BeginEdit: Boolean;
begin
Result := True;
FEdit.Show;
FEdit.SetFocus;
end;
//----------------------------------------------------------------------------------------------------------------------
function TPropertyEditLink.CancelEdit: Boolean;
begin
Result := True;
FEdit.Hide;
end;
//----------------------------------------------------------------------------------------------------------------------
function TPropertyEditLink.EndEdit: Boolean;
var
Data: PPropertyData;
Buffer: array[0..1024] of Char;
S: UTF8String;
begin
Result := True;
Data := FTree.GetNodeData(FNode);
if FEdit is TComboBox then
S := TComboBox(FEdit).Text
else
begin
if FEdit is TCustomEdit then
S := TCustomEdit(FEdit).Text
else
raise Exception.Create('Unknow edit control');
end;
if S <> Data.Value then
begin
Data.Value := S;
Data.Changed := True;
FTree.InvalidateNode(FNode);
end;
FEdit.Hide;
FTree.SetFocus;
end;
//----------------------------------------------------------------------------------------------------------------------
function TPropertyEditLink.GetBounds: TRect;
begin
Result := FEdit.BoundsRect;
end;
//----------------------------------------------------------------------------------------------------------------------
function TPropertyEditLink.PrepareEdit(Tree: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex): Boolean;
var
Data: PPropertyData;
begin
Result := True;
FTree := Tree as TVirtualStringTree;
FNode := Node;
FColumn := Column;
// determine what edit type actually is needed
FEdit.Free;
FEdit := nil;
Data := FTree.GetNodeData(Node);
case Data.ValueType of
vtString:
begin
FEdit := TEdit.Create(nil);
with FEdit as TEdit do
begin
Visible := False;
Parent := Tree;
Text := Data.Value;
OnKeyDown := EditKeyDown;
end;
end;
vtPickString:
begin
FEdit := TComboBox.Create(nil);
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
Text := Data.Value;
Items.Add(Text);
Items.Add('Standard');
Items.Add('Additional');
Items.Add('Win32');
OnKeyDown := EditKeyDown;
end;
end;
vtNumber:
begin
FEdit := TMaskEdit.Create(nil);
with FEdit as TMaskEdit do
begin
Visible := False;
Parent := Tree;
EditMask := '9999';
Text := Data.Value;
OnKeyDown := EditKeyDown;
end;
end;
vtPickNumber:
begin
FEdit := TComboBox.Create(nil);
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
Text := Data.Value;
OnKeyDown := EditKeyDown;
end;
end;
vtMemo:
begin
FEdit := TComboBox.Create(nil);
// In reality this should be a drop down memo but this requires
// a special control.
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
Text := Data.Value;
Items.Add(Data.Value);
OnKeyDown := EditKeyDown;
end;
end;
vtDate:
begin
FEdit := TDateTimePicker.Create(nil);
with FEdit as TDateTimePicker do
begin
Visible := False;
Parent := Tree;
//todo
{
CalColors.MonthBackColor := clWindow;
CalColors.TextColor := clBlack;
CalColors.TitleBackColor := clBtnShadow;
CalColors.TitleTextColor := clBlack;
CalColors.TrailingTextColor := clBtnFace;
Date := StrToDate(Data.Value);
OnKeyDown := EditKeyDown;
}
end;
end;
else
Result := False;
end;
end;
//----------------------------------------------------------------------------------------------------------------------
procedure TPropertyEditLink.ProcessMessage(var Message: TMessage);
begin
FEdit.WindowProc(Message);
end;
//----------------------------------------------------------------------------------------------------------------------
procedure TPropertyEditLink.SetBounds(R: TRect);
var
Dummy: Integer;
begin
// Since we don't want to activate grid extensions in the tree (this would influence how the selection is drawn)
// we have to set the edit's width explicitly to the width of the column.
FTree.Header.Columns.GetColumnBounds(FColumn, Dummy, R.Right);
FEdit.BoundsRect := R;
end;
//---------------- TGridEditLink ---------------------------------------------------------------------------------------
function TGridEditLink.EndEdit: Boolean;
var
Data: PGridData;
Buffer: array[0..1024] of Char;
//S: WideString;
S: String;
I: Integer;
begin
Result := True;
Data := FTree.GetNodeData(FNode);
if FEdit is TComboBox then
begin
S := TComboBox(FEdit).Text;
if S <> Data.Value[FColumn - 1] then
begin
Data.Value[FColumn - 1] := S;
Data.Changed := True;
end;
end
else
if FEdit is TMaskEdit then
begin
I := StrToInt(Trim(TMaskEdit(FEdit).EditText));
if I <> Data.Value[FColumn - 1] then
begin
Data.Value[FColumn - 1] := I;
Data.Changed := True;
end;
end
else
if FEdit is TCustomEdit then
begin
S := TCustomEdit(FEdit).Text;
if S <> Data.Value[FColumn - 1] then
begin
Data.Value[FColumn - 1] := S;
Data.Changed := True;
end;
end
else
raise Exception.Create('Unknow Edit Control');
if Data.Changed then
FTree.InvalidateNode(FNode);
FEdit.Hide;
end;
//----------------------------------------------------------------------------------------------------------------------
function TGridEditLink.PrepareEdit(Tree: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex): Boolean;
var
Data: PGridData;
TempText: String;
begin
Result := True;
FTree := Tree as TVirtualStringTree;
FNode := Node;
FColumn := Column;
// Determine what edit type actually is needed.
FEdit.Free;
FEdit := nil;
Data := FTree.GetNodeData(Node);
case Data.ValueType[FColumn - 1] of
vtString:
begin
FEdit := TEdit.Create(nil);
with FEdit as TEdit do
begin
Visible := False;
Parent := Tree;
TempText:= Data.Value[FColumn - 1];
Text := TempText;
OnKeyDown := EditKeyDown;
end;
end;
vtPickString:
begin
FEdit := TComboBox.Create(nil);
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
TempText:= Data.Value[FColumn - 1];
Text := TempText;
// Here you would usually do a lookup somewhere to get
// values for the combobox. We only add some dummy values.
case FColumn of
2:
begin
Items.Add('John');
Items.Add('Mike');
Items.Add('Barney');
Items.Add('Tim');
end;
3:
begin
Items.Add('Doe');
Items.Add('Lischke');
Items.Add('Miller');
Items.Add('Smith');
end;
end;
OnKeyDown := EditKeyDown;
end;
end;
vtNumber:
begin
FEdit := TMaskEdit.Create(nil);
with FEdit as TMaskEdit do
begin
Visible := False;
Parent := Tree;
EditMask := '9999;0; ';
TempText:= Data.Value[FColumn - 1];
Text := TempText;
OnKeyDown := EditKeyDown;
end;
end;
vtPickNumber:
begin
FEdit := TComboBox.Create(nil);
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
TempText:= Data.Value[FColumn - 1];
Text := TempText;
OnKeyDown := EditKeyDown;
end;
end;
vtMemo:
begin
FEdit := TComboBox.Create(nil);
// In reality this should be a drop down memo but this requires
// a special control.
with FEdit as TComboBox do
begin
Visible := False;
Parent := Tree;
TempText:= Data.Value[FColumn - 1];
Text := TempText;
Items.Add(Data.Value[FColumn - 1]);
OnKeyDown := EditKeyDown;
end;
end;
vtDate:
begin
FEdit := TDateTimePicker.Create(nil);
with FEdit as TDateTimePicker do
begin
Visible := False;
Parent := Tree;
//todo
{
CalColors.MonthBackColor := clWindow;
CalColors.TextColor := clBlack;
CalColors.TitleBackColor := clBtnShadow;
CalColors.TitleTextColor := clBlack;
CalColors.TrailingTextColor := clBtnFace;
Date := StrToDate(Data.Value[FColumn - 1]);
OnKeyDown := EditKeyDown;
}
end;
end;
else
Result := False;
end;
end;
//----------------------------------------------------------------------------------------------------------------------
end.