JVCL的TJvInspector组件使用方法

本文转自：http://www.neugls.info/?p=97

JVCL

The JEDI Visual Component Library (JVCL) consists of a large collection (currently ca 500) visual and non-visual components which can be instantly reused in your Delphi, Kylix and C++ Builder projects. You can visit this website to know more about JVCL: http://jvcl.delphi-jedi.org/; you can download JVCL here.

Introduce

TJvInspector is a component which can let you display properties of an object, it is like delphi's inspect. It may look like this:  The control is completely separated from the editing layer and the editing layer is completely separated from the data layer. This means the control is able to "inspect" a wide variety of data types, without the need of creating a new descendant of the inspector control. It also means you can mix various data sources in one view. The control does not handle the painting itself. This is left to a painter object. Each of the properties is called an item, a instance of TJvCustomInspectorItem. TJvCustomInspectorItem is the base inspector item. An item is responsible for drawing and editing the underlying data object, as well as managing the sub items. The base class introduces methods and properties to:

• display and edit the data object
• manage child items

The base class itself can be used as a read only item with no underlying data object. An instance of this class is used as the root item for the inspector. The standard package provides various item classes to edit the different types of data:

• Ordinals
• Enumerations
• Sets
• Strings
• Floats

In addition it provides an item class that functions as a category holder. A category holder also has no data instance to provide values. Categories can be nested, but each item can belong to only one category.

Usage

• How to edit properties of a component?
• How to add a category?
• How to edit a property?
• How to edit a string?
• How to edit font?
• How to edit font name?
• How to edit simple data types?
• How to edit color?

How to edit properties of a component?

By using the AddComponent method of TJvCustomInspector  you can edit the properties of the component, like:

procedure TSimpleMainForm.FormShow(Sender: TObject);
begin
  JvInspector1.Clear;
  JvInspector1.AddComponent(Self, 'A Form Inspecting Itself', True);
end;

You can also do it like this:

procedure TForm1.FormCreate(Sender: TObject);
var
  InspCat: TJvInspectorCustomCategoryItem;
begin
  InspCat:=TJvInspectorCustomCategoryItem.Create(self.JvInspector1.Root,nil);
  InspCat.DisplayName:='Form1';
  TJvInspectorPropData.New(InspCat,Self);
end;

How to add a category?

You can also do it like this:

procedure TForm1.FormCreate(Sender: TObject);
var
  InspCat: TJvInspectorCustomCategoryItem;
begin
  InspCat:=TJvInspectorCustomCategoryItem.Create(self.JvInspector1.Root,nil);
  InspCat.DisplayName:='Form1';
  TJvInspectorPropData.New(InspCat,Self);
end;

How to edit a property?

By using the New method of TJvInspectorPropData, we can edit a property of an object, such as:

TJvInspectorPropData.New(InspCat, JvInspector1, GetPropInfo(JvInspector1, PropArray[I, 0])).

Detial usage you can consult the help

How to edit a string?

TJvInspectorVarData.New(InspCat,'DisplayName',TypeInfo(String),@MyString);

How to edit font?

var
  Form1: TForm1;
  FColor:Integer=clRed;
  MyString:string='aa';
  Font:TFont;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  InspCat: TJvInspectorCustomCategoryItem;
begin
  InspCat:=TJvInspectorCustomCategoryItem.Create(self.JvInspector1.Root,nil);
  InspCat.DisplayName:='Property';

  Font:=TFont.Create;
  TJvInspectorVarData.New(InspCat,'DisplayName',TypeInfo(String),@MyString);
  TJvInspectorVarData.New(InspCat,'Font',TypeInfo(TFont),@Font);

  InspCat.Expanded:=True;
end;

Note: The 4th parameters of the procedure TJvInspectorVarData.New could not be local variables.

How to edit font name?

  MyFontName:string='Tahoma';

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  InspCat: TJvInspectorCustomCategoryItem;
begin
  InspCat:=TJvInspectorCustomCategoryItem.Create(self.JvInspector1.Root,nil);
  InspCat.DisplayName:='Property';

  TJvInspectorVarData.ItemRegister.Add(TJvInspectorTypeInfoRegItem.Create(TJvInspectorFontNameItem,TypeInfo(String)));
  TJvInspectorVarData.New(InspCat,'FontName',TypeInfo(String),@MyFontName);

  InspCat.Expanded:=True;

end;

How to edit simple data types?

With TJvInspectorVarData, we can edit Simple data types, such as:

TJvInspectorVarData.New(InspCat,'FontName',TypeInfo(String),@MyFontName);

TJvInspectorVarData is the inspector data layer that obtains its data from a simple variable or some value on the heap. The class implements all access properties, but the type info will be used to check the legality of the access (ie. a float can't be accessed as Int64).

How to edit color?

JVCL provider us a class called TJvInspectorColorItem which can let'us edit TColor properties. You can use it like this:

FColor:TColor

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  InspCat: TJvInspectorCustomCategoryItem;
begin
  InspCat:=TJvInspectorCustomCategoryItem.Create(self.JvInspector1.Root,nil);
  InspCat.DisplayName:='Property';

  TJvInspectorVarData.ItemRegister.Add(TJvInspectorTypeInfoRegItem.Create(TJvInspectorColorItem,TypeInfo(TColor)));
  TJvInspectorVarData.New(InspCat,'Color',TypeInfo(TColor),@FColor);

  InspCat.Expanded:=True;

end;

How to make your own item?

In this section, I will show you an example to demonstrate how to make your own item. Following shows the code:

(*
 * Author : Neugls.
 * Website: Http://www.neugls.info
 * Email  : NeuglsWorkStudio@gmail.com
 *)
unit NuColorInspectItem;

interface
uses JvInspector,Graphics,Types;
type
  TJvInspectorColorItem = class(TJvCustomInspectorItem)
  private
  protected
    function NameForColor(const Color: TColor): string;
    procedure PaintValue(const Color: TColor; const ColorName: string;const ACanvas: TCanvas; const ARect: TRect);
    procedure SetFlags(const Value: TInspectorItemFlags); override;
    procedure SetRects(const RectKind: TInspectorPaintRect; Value: TRect); override;
    procedure ButtonClick(Sender: TObject); override;
    function GetDisplayValue: string; override;
    procedure SetDisplayValue(const Value: string); override;
  public
    constructor Create(const AParent: TJvCustomInspectorItem;
      const AData: TJvCustomInspectorData); override;
    procedure BeforeDestruction; override;
    procedure DrawValue(const ACanvas: TCanvas); override;
    class procedure RegisterAsDefaultItem;
    class procedure UnregisterAsDefaultItem;
  end;

implementation
uses JvResources,SysUtils,Dialogs,Windows;

function Color2RGB(Color:TColor):Integer;
begin
  Result:=0;
  Result:=Result or((Color and $FF) shl 16);
  //Result:=Result or(Color shl 16);
  Result:=Result or(((Color shr 8) and $FF) shl 8);
  //Result:=Result or(Color and $0000FF00);
  Result:=Result or(((Color shr 16) and $FF));
end;

//=== { TJvInspectorColorItem } ==============================================

procedure TJvInspectorColorItem.ButtonClick(Sender: TObject);
var
  ColorDlg:TColorDialog;
begin
  ColorDlg:=TColorDialog.Create(nil);
  try
    if ColorDlg.Execute then
    begin
      //DisplayValue:=NameForColor(FColor);
      Data.AsOrdinal:=ColorDlg.Color;
    end;
  finally
    ColorDlg.Free;
  end;
  inherited;
end;

constructor TJvInspectorColorItem.Create(const AParent: TJvCustomInspectorItem;
  const AData: TJvCustomInspectorData);
begin
  inherited Create(AParent, AData);
  Flags := [iifVisible, iifEditButton,iifEditFixed];
end;

function TJvInspectorColorItem.NameForColor(const Color: TColor): string;
var
  RGBColor:Integer;
begin
  RGBColor:=Color2RGB(Color);
  Result := '0x'+IntToHex(RGBColor,6);
end;

procedure TJvInspectorColorItem.PaintValue(const Color: TColor; const ColorName: string;
  const ACanvas: TCanvas; const ARect: TRect);
var
  TH: Integer;
  BoxRect: TRect;
  bc: TColor;
  pc: TColor;
  txtRect: TRect;
begin
  TH := Rects[iprValue].Bottom - Rects[iprValue].Top - 2;
  BoxRect.Left := ARect.Left + (ARect.Bottom - ARect.Top - TH) div 2;
  BoxRect.Top := ARect.Top + BoxRect.Left - ARect.Left;
  BoxRect.Right := BoxRect.Left + TH;
  BoxRect.Bottom := BoxRect.Top + TH;
  with ACanvas do
  begin
    if Color <> clNone then
    begin
      bc := Brush.Color;
      pc := Pen.Color;
      try
        Brush.Color := Color;
        //Pen.Color := BorderColor(bc, Color);
        Rectangle(BoxRect);
      finally
        Pen.Color := pc;
        Brush.Color := bc;
      end;
    end;
   txtRect := ARect;
   txtRect.Left := txtRect.Left + (txtRect.Bottom-txtRect.Top)+ 1;
   TextRect(txtRect, txtRect.Left, BoxRect.Top, ColorName);
  end;
end;

procedure TJvInspectorColorItem.SetDisplayValue(const Value: string);
begin
  inherited;
  OutputDebugString(PWideChar(Value));
end;

procedure TJvInspectorColorItem.SetFlags(const Value: TInspectorItemFlags);
begin
  inherited SetFlags(Value + [iifEditButton,iifEditFixed]);
end;

procedure TJvInspectorColorItem.SetRects(const RectKind: TInspectorPaintRect; Value: TRect);
begin
  if RectKind = iprValue then
    Value.Left := Value.Left + (Value.Bottom - Value.Top) + 2;
  inherited SetRects(RectKind, Value);
end;

procedure TJvInspectorColorItem.BeforeDestruction;
begin

  inherited BeforeDestruction;
end;

procedure TJvInspectorColorItem.DrawValue(const ACanvas: TCanvas);
var
  Color: TColor;
  S: string;
  ARect: TRect;
  SafeColor: TColor;
begin
  Color := clNone;
  if Data = nil then
    S := RsJvInspItemUnInitialized
  else
  try
    if not Data.IsInitialized then
      S := RsJvInspItemUnInitialized
    else
    if not Data.HasValue then
      S := RsJvInspItemNoValue
    else
    if not Data.IsAssigned then
      S := RsJvInspItemUnassigned
    else
    begin
      S := DisplayValue;
      Color := Data.AsOrdinal;
    end;
  except
    S := RsJvInspItemValueException + ExceptObject.ClassName + ': ' +
      Exception(ExceptObject).Message;
  end;
  ARect := Rects[iprValueArea];
  SafeColor := ACanvas.Brush.Color;
  if Editing then
    ACanvas.Brush.Color := clWindow;
  try
    ACanvas.FillRect(ARect);
    PaintValue(Color, S, ACanvas, ARect);
    if Editing then
      DrawEditor(ACanvas);
  finally
    if Editing then
      ACanvas.Brush.Color := SafeColor;
  end;
end;

function TJvInspectorColorItem.GetDisplayValue: string;
begin
  Result:=NameForColor(Data.AsOrdinal);
end;

class procedure TJvInspectorColorItem.RegisterAsDefaultItem;
begin
  with TJvCustomInspectorData.ItemRegister do
    if IndexOf(Self) = -1 then
      Add(TJvInspectorTypeInfoRegItem.Create(Self, TypeInfo(TColor)));
end;

class procedure TJvInspectorColorItem.UnregisterAsDefaultItem;
begin
  TJvCustomInspectorData.ItemRegister.Delete(Self);
end;

end.

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