DAVSL Samples

	DAVSL Samples
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Installation

Simply create a directory in some convenient location, copy the Zip file there, and unzip. This should result in several subdirectories:

...\DAVSL	Contains units common to any DAVSL-based VSL project.
...\otherdirs	Contain various individual sample VSL projects

There are no components to install.

Project Structure

Each of the samples includes an xxx.dpr project file, which in Delphi serves to define the DLL's entry points. For a VSL this means the VisioLibMain procedure. The dpr file, as usual with any Delphi project, specifies other files to compile into the project (and this list can also be viewed in the Delphi Project Manager window). Each project includes several files from the DAVSL directory, along with one or a few others specific to the particular VSL. A typical project looks something like this:

File category	Directory	Filename	Description
Specific to particular VSL	...\MyVSLDir	MyVSL.dpr	Project file. Copy generic VSL dpr and edit the external fielname and internal library name only. (eg: Library MyVSL;)
		MyVSL_AddOns.pas	Unit in which to declare and implement addons. These can provide the actual functionality too, or act simply as intermediaries to othe objects/units where the real functionality happens. See the Architecture discussion. (You can have more such addon units if need be -- see how addons register themselves with the VSL object in the unit initialization sections.)
		MyVSL_Control.pas	Where the addons are simple intermediaries, this unit would provide the main implementation (and of course you can have any number more such units).
Common to all VSLs	...\DAVSL	DAVAO.pas	Translation of types and constants from VAO.h
		DAVSL.pas	TVSL manager object; Base TAddOn object
		DAVSL_Util.pas	Some supporting functions
		DAVSL_About	Standard About dialog
	whereever	Visio_TLB	This is the Visio type library generated with Delphi Import Type Library feature. This should either be included in the project, or in the default Library path (such as in $(DELPHI)\Imports). The DAVSL package includes a Visio_TLB in the ...\DAVSL directory in case you are unfamiliar with using the Import Type Lib feature.

Getting A Sample Running

To get a sample running, open one of the sample directories, and double click the dpr file, or use Delphi to open it. You may need to perform one or more of the following steps:

Create a directory where your VSL DLLs will reside and be found by Visio, for example ..\Visio\Solutions\MyVSLs
Set Project > Options > Output directory accordingly
In Project > Version Info set some version info
Compile and verify that Delphi produced a VSL in the solution directory.
Launch Visio, and exercise the demo according to the descriptions for the individual demos.
Don't forget to put Visio in Developer mode, so that the Tools > Add-Ons menu is available.
To run Visio and a VSL under Delphi's debugger, you will need to specify the application to run (ie: Visio) in Delphi's Run > Parameters dialog. You might also specify a document to load if repeatedly testing with same doc.

Details on Individual Demos

DAVSLBeep

Trivial VSL which provides a single AddOn (function): DAVSLBeep_Beep. You can fire this AddOn using the Tools > Add-Ons menu, or create a shape with an Action which uses:

RUNADDON("DAVSLBeep_Beep")

Needless to say it sounds a "Beep-Beep" from the PC speaker. The structure of the VSL project demonstrates the minimal basics for a DAVSL-style VSL.

DAVSLColorForm

This sample demonstrates using a Delphi form as a modeless dialog to control Visio.

Launch Visio and drop a shape on the drawing page.
Activate DAVSLColorForm_Open from the Tools > Add-Ons menu, the DAVSLColorForm dialog should appear.
Select a shape on the drawing, and use the dialog's buttons to change the shape's fill color.
Minimize Visio and note that the dialog minimizes too.

DAVSLShapeChange

Demonstrates supplying arguments to an AddOn (eg: using the RUNADDONWARGS ShapeSheet function). Also demos the About feature.

Launch Visio and open the supplied Demo_ShapeChange.vsd document
Try the shape's right-click items (Blue-Green and 90-degrees). (Note: if these don't immediately work, force Visio to refesh its addon cache by selecting the Tools > Add-Ons menu item. No need to run an addon, just listing them should be sufficient.) After applying the addon's changes, you can restore the shape with regular Visio menus or toolbuttons.
Inspect the shape's ShapeSheet ShapeSheet Action section to see how the arguments are set up.
To see description of available arguments, use Tools > Add-Ons > Run Add-on, select DAVSLShapeChange_Color, and click About.
Note how structure of units follows scheme described in Architecture page.

DAVSLArgs

Demonstrates the arguments that a VSL receives, depending on how it is called.

Launch Visio and open the supplied DAVSLArgs.vsd drawing.
Right-click the shape and select Args.
The AddOn's window will show the arguments that Visio passes.
Note that this window is modal, compared to modeless windows in other examples.
Note that the VSL object which parses the arguments into a TStringList also strips of any leading slash (which Visio customarily supplies for the default arguments.).
See also the VSL Arguments discussion in the Technical Notes page.

DAVSLEvents

Demonstrates how a VSL responds to Visio events (Connection Add and Delete).

Launch Visio
Use Tools > Add-Ons > Run Add-on and select DAVSLEvents_Show
Create a drawing with some shapes and connectors.
Watch the Events window as you glue and unglue connectors.

Code notes:

Unit DAVSLEvents_Events contains a Delphi object that implements the COM IVisioAddOnSink interface needed to receive event notifications from Visio.
DAVisioAddonSink.tlb contains the type library for IVisioAddOnSink.
The DAVSL_IncludeEvents unit tells Delphi to build the type library information into the DLL. This is needed so that the DAVSLEvents_Events unit can use a call to TAutoObjectFactory.Create to initialize an object factory for use in creating TVisioAddOnSink objects. (Note that it is not necessary to register this type library in the Registry.)
DAVisioAddOnSink_TLB.pas is a standard Delphi unit generated by the Type Library editor declaring the IVisioAddOnSink for use in Delphi (in much the same way as Visio_TLB.pas declares the interfaces to Visio for use in Delphi.)
The DAVSLEvents_Control unit contains the heart of the VSL, including hooking up and unhooking event monitoring, and handling event notifications passed along via the VisioAddOnSink object.
Note how the EventController object maintains its own IVisioAddOnSink reference, despite already having a TVisioAddOnSink reference. If this were not the case, after adding an event and then deleting the event, the references to VisioAddOnSink would have incremented then decremented back to zero, at which point the VisioAddOnSink would be released. Instead, we want it to stay around even when no event objects are actually referencing it.

Article Created: 2000-09-20 Last edit: Last edit: 00-10-30 Graham Wideman
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