Using SftTree/OCX with Delphi 7 and Newer
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Using SftTree/OCX with Delphi 7 and Newer |
This section describes how SftTree/OCX is typically used with Delphi 7 and other, older versions of Delphi. For information on how to use this product with more recent Delphi versions, such as Delphi 2007, please see "Using SftTree/OCX with Delphi 2005 And Newer".
The SftTree/OCX control must be added to the Component Palette before it can be used in a project.
The control is added to the Component Palette using the Component, Import ActiveX Control... menu command, which displays the following dialog:
Select the control "SftTree/OCX 6.5 Tree Control (Version 6.5)" by highlighting it and click Install. Make sure to select "SftTree/OCX 6.5 Tree Control" and not the control named "SftTree/OCX 6.5 Tree Control (IE)" as that control is specific to Internet Explorer and HTML pages. Click "Install...".
In the resulting dialog you are prompted to save the definition into a new or existing package. Enter a suitable new package name or select an existing package name (such as "Borland User Components") and click OK.
Click Yes once you are prompted to build and install the new package.
Now the control has been added to the Component Palette under the ActiveX tab. If an error message is displayed instead, the product SftTree/OCX is not correctly installed or the control may have been unregistered accidentally. Quit Delphi and use the entry Maintenance, Register SftTree OCX in Windows Registry in the SftTree/OCX 6.5 program group to register the control. Restart Delphi and try to add the control to the Component Palette again.
After the control has been added to the Delphi Component Palette, the Imports directory in the Delphi product location contains the file SftTreeLib65_TLB.pas. This file has been generated by Delphi and contains all property and method definitions. The generated file should be used as a reference. Please note that the Pascal definitions are generated by Delphi and are not part of SftTree/OCX.
This adds the following SftTree/OCX controls to the Component Palette.
for
use with Delphi (and other development tools)
for
use with other development tools (do not
use with Delphi)
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If the icon appears with a small "e" in the top left corner as shown on the right, you have accidentally added the wrong control to the Component Palette. This control is specific to Internet Explorer and HTML pages. Remove the control, then add the correct control by following the above instructions. |
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Now the control can be added to a form by clicking on the SftTree/OCX button of the Component Palette (ActiveX tab).
All required steps have now been completed to use SftTree/OCX.
For a complete example, add the following sample code to initialize the control:
procedure TForm1.FormCreate(Sender: TObject);
var
index : Integer;
begin
index := SftTree1.Items.Add('Item 1');
index := SftTree1.Items.Add('Item 2');
SftTree1.Item[index].Level := 1;
index := SftTree1.Items.Add('Item 3');
end;
In this example, the control is initialized at run-time using code. Of course it is also possible (and much easier) to set up all properties using the property pages. You can access the property pages by right-clicking on the control and select the Properties... entry of the popup menu.
You can run the sample application and it displays a SftTree/OCX control with three items.
After adding the control to the form, right click on the control and select the Properties... entry of the popup menu. This displays the Property Dialog for the control.
Please note that you can right-click on a property in a Property Dialog or double-click on the description of a property to access its complete help information.
This control has many properties and methods which you can use. This is a very simple example and doesn't even begin to exploit the capabilities of this control. Please take a moment to familiarize yourself with the objects offered by the SftTree/OCX control. Each object represents a specific area of the control and can be fully customized. Also make sure to run the demo which is included with this product and take a look at the included samples.
When adding SftTree/OCX to a project, Delphi generates a class wrapper to fully support an ActiveX control such as SftTree/OCX. After the control has been added to the Delphi Component Palette, the Imports directory in the Delphi product location contains the file SftTreeLib65_TLB.pas. This file has been generated by Delphi and contains all property and method definitions. The generated file should be used as a reference. Please note that the Pascal definitions are generated by Delphi and are not part of SftTree/OCX.
While some graphics properties are generated to use a TPicture type, many properties and methods do not. These use the OLE picture type IPictureDisp instead, which cannot directly be used with a TPicture type. The Syntax portion of each method, property and event shows the full syntax and required picture type (TPicture or IPictureDisp).
The TPicture type can easily be converted into an IPictureDisp type using Delphi's GetOlePicture function.
The Cell.Image property (for example) can now be used as follows:
uses ActiveX
. . .
var
pOLEPic : IPictureDisp;
. . .
GetOlePicture(Image1.Picture, pOLEPic);
SftTree1.Cell[0,0].Image.Picture := pOLEPic;
In this example, Image1 is an image control, part of the form, containing an image.
The Syntax section of picture properties typically shows Get, Put and PutRef forms. If both Put and PutRef are available, PutRef is the preferred form as it conserves resources and assigns a picture object reference to the control. Put causes the control to completely copy the picture object.
While some font properties are generated to use a TFont type, many properties and methods do not. These use the OLE font type IFontDisp instead, which cannot directly be used with a TFont type. The Syntax portion of each method, property and event shows the full syntax and required font type (TFont or IFontDisp).
The TFont type can easily be converted into a IFontDisp type using Delphi's GetOleFont function.
The SftTreeCell.Font property (for example) can now be used as follows:
uses ActiveX
. . .
var
f : TFont;
pFont : IFontDisp;
. . .
f := TFont.Create();
f.Name := 'Times New Roman';
f.Size := 16;
GetOleFont(f, pFont);
SftTree1.Cell[0,0].Font := pFont;
The Syntax section of font properties typically shows Get, Put and PutRef forms. If both Put and PutRef are available, PutRef is the preferred form as it conserves resources and assigns a font object reference to the control. Any change to the font object is reflected in the control also. Put on the other hand causes the control to completely copy the font object.
Color properties (without parameters) of the SftTree object use the Delphi TColor type, but all other properties and objects (such as SftTreeCell, etc.) use the Cardinal type. Converting a Delphi TColor type to a Cardinal (OLE color value) is easily accomplished using the Cardinal conversion.
The valid range for a color value is 0 to 16,777,215 ($00ffffff). The high order byte of a number in this range equals 0; the lower 3 bytes, from least to most significant byte, determine the amount of red, green, and blue, respectively. The red, green, and blue components are each represented by a number between 0 and 255 ($FF). If the high byte is not 0, the system colors as defined in Control Panel's settings are used. The Windows API GetSysColor defines all valid constants. Please see your development environment's documentation for applicable color constants.
The Syntax portion of each method and property shows whether a TColor type or an OLE color of type Cardinal is used.
TColor Type
var c : TColor;
SftTree1.BackColor := clHighlight; SftTree1.BackColor := clRed; SftTree1.BackColor := $000000FF; // red
c := SftTree1.BackColor;
OLE Color Value
var c : TColor;
SftTree1.Cell[0,0].BackColor := Cardinal(clHighlight); SftTree1.Cell[0,0].BackColor := Cardinal(clRed); SftTree1.Cell[0,0].BackColor := $000000FF; // red
c := SftTree1.Cell[0,0].BackColor;
The main control is represented by an object of the class TSftTree, but can also be represented by its ISftTree interface. The ISftTree interface can be retrieved using the Direct property.
Certain methods and properties have different names and return types, based on how they are accessed. While (for example) an object based on the TSftTree class is mostly equivalent to the ISftTree interface exposed by the control, Delphi can introduce minor differences. Such differences are shown in the Syntax section of the affected methods and properties. All other objects are identical to their interfaces and no distinction is made.
The Syntax portion shows both forms, the class member and the interface method (the interface method is always marked with a Note indicator). If both forms are identical, only one entry is shown.
Some properties (particularly font and picture properties) may require different types. For example, the Font property accepts a TFont object when accessed through a TSftTree class object, but uses a IFontDisp interface pointer when accessed directly though the ISftTree interface pointer. IFontDisp can be provided using the GetOLEFont function.