DataViews Visual C++ Tutorial Guide. DataViews for Windows Version 2.2

Transcription

1 DataViews Visual C++ Tutorial Guide DataViews for Windows Version 2.2

2 Introduction GE Fanuc DataViews Corporate Headquarters 47 Pleasant Street Northampton, MA U.S.A. Telephone:(413) FAX:(413) web: GE Fanuc DataViews Japan Operations 16 Parale Mitsui Bldg 8 Higashida-cho Kawasaki-ku, Kawasaki Kanagawa, , Japan. Telephone: FAX: dv-japan@dvcorp.com GE Fanuc DataViews U.K. Sales Office 1210 Parkview Arlington Business Park Theale, Reading, RG7 4SA United Kingdom Telephone: FAX: info@dataviews.co.uk web: Copyrights and Trademarks Copyright 2000 GE Fanuc DataViews All Rights Reserved. This manual is subject to copyright protection. No portion of the contents of this book may be reproduced in any form or by any means without prior written consent from GE Fanuc DataViews. DataViews, DV-Tools, and DV-Draw are registered trademarks of GE Fanuc DataViews. DVX-Designer is a trademarks of GE Fanuc DataViews. All other trademarks are acknowledged as the property of their respective owners. August 2000 Software Release Version 2.2 Document Number Document Revision D

3 iii DataViews Visual C++ Tutorial Guide Table of Contents Introduction... 1 Chapter 1: Deploying Your View in a Visual C++ Application... 3 DataViews Visual C++ Tutorial Overview... 3 Adding Windows Controls to the View... 5 Creating a Dialog Application Adding Code to Display a View Manipulating Objects Displayed in the Custom Control Building and Running the Application For More Information Index... 31

4

5 1 Introduction Intro DataViews is a powerful development tool that lets you create complex applications for monitoring and controlling live data processes. DataViews provides several tools for developing applications from beginning to end. These tools include: DV-Draw Editor With the DV-Draw editor, you can create detailed drawings for your application. You can create custom objects, save them to a palette, and use the palette to create instances of these objects. Custom objects can include dynamics and embedded bitmaps. Some DataViews objects are inherently dynamic, such as graphs, and you can add dynamic behavior to other objects. You can connect dynamics to various kinds of data, including ODBC databases and custom data sources. You can add rules to manage view navigation, to overlay other views or objects from other views, to pop up objects from other views, and to control data values and run speed. With multiple views, these rules let you construct a working interface right in the DV-Draw editor. DataViews C++ Class Library The DataViews C++ class library allows you to integrate your DataViews interface into a C++ application and makes view management and object manipulation available to Visual C++ programmers. This tutorial demonstrates how to create and run a dynamic interface in DV-Draw, and how to build a Visual C++ application using the DataViews CDVCustomControl class. The tutorial does not demonstrate all possible features or capabilities of the product, but leads you through basic procedures for building and deploying an interface. The remaining documentation provided with your release describes all DV-Draw and API features in detail.

6

7 3 Chapter 1 1 Deploying Your View in a Visual C++ Application 1 In the DV-Draw Tutorial Guide, you learned how to use DV-Draw to create graphical views containing data-driven dynamic objects, and you learned how to deploy DataViews views using Visual Basic and the DVPlayer ActiveX control. In this tutorial, you learn how to take your work in DV-Draw and deploy it in a Visual C++ application using Microsoft Developer Studio. In this tutorial, we create a dialog-based application using the DataViews CDVCustomControl class in the Microsoft Visual C programming environment. The CDVCustomControl class lets you add DataViews views to a Visual C++ application. Topics covered in this tutorial include: DataViews Visual C++ Tutorial Overview Adding Windows Controls to the View Creating a Dialog Application Adding Code to Display a View Manipulating Objects Displayed in the Custom Control Building and Running the Application DataViews Visual C++ Tutorial Overview This tutorial demonstrates the use of the DataViews custom control in a Visual C++ project. This section introduces this example and discusses points of interest.

8 4 DataViews Visual C++ Tutorial Guide The following figure shows the completed application. The application consists of a Visual C++ dialog that contains the DataViews custom control and several standard controls such as text boxes, push buttons and radio buttons. In addition, the application displays a view that contains an MFC slider control. In this tutorial, we will add the control to the view and see how you handle user input to see new data in the graph. This C++ application displays a DataViews view file using a specialized control, in this case, the DataViews custom control. The view file is based on the view created in the DV-Draw Tutorial Guide. It contains a graph object and three custom objects representing dials. The other controls in the application allow you to change the graph s title, the number of data iterations, and the graph type. You can also stop and restart the updating of the graph s data. Note that this tutorial assumes some familiarity with Microsoft Developer Studio. The view files as well as the code shown in this tutorial can be found in the <dataviews>\tutorials\mfctutorial directory. The example was created using Developer Studio. You can build and run the example at any time. It is not necessary for you to follow the instructions and create the example yourself, but the instructions do include all of the code for the example.

9 Chapter 1: Deploying Your View in a Visual C++ Application 5 Background information about the DataViews classes, code generation, and Windows control geometry is provided in the on-line documentation. Adding Windows Controls to the View Before we describe how to create a C++ application that uses DataViews views, we need to make some modifications to the top.v view created in the DV-Draw Tutorial Guide. In this tutorial, we want to outline the steps required to handle events off of the DataViews view in an MFC application. This type of work requires specific rules applied to a DataViews view. To emphasize this point, we add a horizontal MFC slider control to the top.v view developed in the DV-Draw Tutorial Guide, and add a memory data source for the slider. We will also apply two rules on the view: one that will create an OnAfterAttach() event handler; and one that will create an OnHorizontalScroll() event handler. Finally, we generate C++ header and implementation files for the new view. In this way, we can incorporate the DataViews view into an MFC application and demonstrate event handling using MFC controls embedded within the view. AddingaSliderControltotheView 1. Open the view in DV-Draw. If you choose to use the view you created in thethe DV-Draw Tutorial Guide, then load the view into DV-Draw. Alternatively, you can make a copy of the top.v view file, and the Gauge.sd subdrawing file, from the <dataviews>\tutorials\chapter1 directory, place the copies in your current working area, and use the view as a starting point for this tutorial. 2. Display the Controls Toolbar. When you first run DV-Draw, the MFC Controls Toolbar is not visible. In order to display it, select Customize... under the Tools menu. This displays the Customize dialog. Select Controls to display the MFC Controls toolbar. Select Close on the Customize dialog to dismiss it.

10 6 DataViews Visual C++ Tutorial Guide 3. Add an MFC slider control to your view. Select the slider control,, on the MFC Controls toolbar. Click and drag in your loaded view to place the slider in the view. You can place the slider anywhere you wish. You can also resize the slider to any size. In this tutorial, we resized the graph and placed the slider between the graph and the capacity, pressure, and temperature arrows. You new view should appear similar to the following figure: New MFC Slider Control

11 Chapter 1: Deploying Your View in a Visual C++ Application 7 Adding a Data Variable to the Graph In this tutorial, we want to be able to manipulate the slider control in our view, and see data changing in the graph. To do this, we need to add a data source and data variable to the graph that the slider will ultimately use to control data values in the graph. 1. Open the Graph Properties dialog. With the view loaded, double-click the graph in DV-Draw to display the Graph Properties dialog. 2. Open the Graph Editor dialog. Select More Properties... in the General tab to display the Graph Editor dialog. 3. Create a memory data source. Select the Variables tab of the Graph Editor dialog. In the Variables section of the tab, add a new data variable by selecting. This displays the Data Selection for Graphs dialog. The slider control requires a memory data source. Create a new memory data source for the graph by selecting Memory from the New Data Source combo box and clicking. This create a default memory data source called default.mem. 4. Create a memory data variable. Select to add a new variable to the memory data source. Choose the Edit>> button and change the data variable name from its default value to read slider.

12 8 DataViews Visual C++ Tutorial Guide The new data source and data variable should appear along with the other graph variables as in the following figure: New memory data source and data variable Dismiss the Data Selection for Graphs dialog with your changes by clicking OK. In the Graph Editor, click OK to add the new data variable to the graph and dismiss the dialog. Close any other open dialogs when you are finished. Adding Rules to the View RecallthatintheDV-Draw Tutorial Guide, we added a rule to the top.v view file that switches the displayed view file when the user clicks on the view background.

13 Chapter 1: Deploying Your View in a Visual C++ Application 9 The following steps describe adding two new rules to your view file in DV-Draw. One rule creates an OnAfterAttach() event handler; and the other creates an OnHorizontalScroll() event handler. These event handlers will be utilized later in this tutorial when we apply the view to an MFC application. 1. Open the View Properties dialog for the loaded view. Double-click on the background of the view to display the View Properties dialog. Select the Rules Tab. 2. Add an AfterAttach event rule to the view. To add a rule to the view, select to create a new rule. By default, a rule is created for you such that no actions occur in the event of a mouse pick. We would like to replace this default rule and create a rule such that after the view is attached to the interface of our application, an OnAfterAttach() event handler is called. In the Event column, select the combo box to display a listing of available events for the view. Choose After Attach from the listing. Leave the Condition as Always and in the Action column, pull down the combo box, scroll to the bottom of the list and choose Call Generated Handler. You may need to resize the columns in the Rules tab to view the various listings, however, your new rule should as in the following figure:

14 10 DataViews Visual C++ Tutorial Guide 3. Add a Horizontal Scroll event rule to the view. Perform the same operations as in the previous step, except choosing the On Horizontal Scroll event in the Event column. After choosing Call Generated Handler in the Action column, your two new rules should appear as in the following figure: Now we are ready to generate C++ header and implementation files for the new view. Generating Code in DV-Draw In order to use the new view and its rules in our C++ application, we need to generate code using DV-Draw. The code files will be incorporated into an MFC application where we will use the event handlers. 1. Set up a new working directory. For the purposes of this tutorial, create a separate working directory from where DataViews is installed. Create a directory called MFCTutorial. 2. Save the view in DV-Draw. We want to save the new view file under a different name, so choose the Save As... option under the File menu to display the Save As... file selection dialog. Locate your new working directory, MFCTutorial, and save the new file as GraphView.v.

15 Chapter 1: Deploying Your View in a Visual C++ Application Generate code for the view. Select Code Generation... under the View menu to display the Code Generation dialog. Use the default settings and select Generate Code. Select Close to dismiss the dialog. 4. Exit DV-Draw. Select the Exit option under the File menu to close the DV-Draw editor. Now that we have generated C++ code and header files for our view, we are ready to start building our C++ application that will display the view and allow us to interact with the view s graphical objects. Creating a Dialog Application You can display a view that contains Windows control objects in a dialog application. The following instructions show how to create a custom control in a dialog application. These procedures are: Creating the Dialog Application in Developer Studio Setting Up the Dialog Creating the Custom Control Creating the Dialog Application in Developer Studio This procedure creates a dialog application in the Microsoft Developer Studio. 1. Create a new workspace. In Developer Studio, pull down the File menu and select the New option. This displays the New dialog 2. Select an application wizard. In the New dialog, go to the Projects tab. This displays a selection of Wizard options. Select MFC AppWizard (exe). 3. Enter a name for your project. For the purposes of this tutorial, make sure you choose the directory where we generated code for our view, namely the MFCTutorial directory. Enter the following project name: MFCTutorial

16 12 DataViews Visual C++ Tutorial Guide 4. Start the MFC AppWizard. Click on OK. This displays the MFC AppWizard. 5. Select the type of application. The first screen of the MFC AppWizard displays the different kind of applications you can create. Select Dialog-based and click on Next. Leave the remaining settings as they are. You can now click on Finish. The New Project Information dialog displays the specifications for your new application. If you are satisfied with the specifications, click on OK. If you want to change any of the specifications, you can click on Cancel to dismiss the New Project Information dialog. You can use the Back button in the MFC AppWizard to return to the screen where you want to make changes. The project workspace creates the classes, resources, and files for your application. If you expand each list, you can see the new files in your project workspace. Note that the view file and the generated code files should also be in the same directory. Setting Up the Dialog Developer Studio creates a default dialog for you when you elect to create a dialogbased application. The dialog is visible under ResourceView of Developer Studio. The dialog contains an OK button, a Cancel button, and a static text object: We made the following modifications to the default dialog: Resized the dialog so it is larger. Deleted the static text object. Deleted the Cancel button. Moved the OK button to the bottom right hand side of the dialog and relabeled the button to read Quit.

17 Chapter 1: Deploying Your View in a Visual C++ Application 13 Creating the Custom Control The control palette lets you create controls. We used the following procedure to create a custom control inside the dialog. 1. Add the Custom Control to the dialog. Select the custom control button,, then click and drag inside the dialog to specify the size and location of the custom control. To maintain the aspect ratio of the view when it is displayed, the custom control should be approximately square. 2. Display the Custom Control Properties dialog. With the custom control selected, click right and select Properties from the context menu. This displays the Custom Control Properties dialog. 3. Enter the Custom Control class name. In the Class field of the Custom Control Properties dialog, enter: DVCustomControl Note that the ID of the custom control is IDC_CUSTOM1. In your own application, you can change this name, but for the purposes of this exercise, we will keep this default ID. You now have a custom control of class CDVCustomControl in your dialog application. The dialog should appear as in the following figure: DVCustom Control

18 14 DataViews Visual C++ Tutorial Guide Adding Code to Display a View This section shows all the code we added to our application. In the following procedures, we: Add the generated GraphView files to the application. Add #includes. Add declarations. Add initialization. Add code to attach GraphView.v to the custom control. Add code to detach and destroy the view. Adding the Generated View Files In order to incorporate GraphView.v into your application, you must add the generated header and implementation files to the application. These are the files that were generated by DV-Draw in the Generating Code in DV-Draw section of this tutorial. 1. Display the Insert Files Into Project dialog. Pull down the Project menu, select Add To Project, and select Files. This displays a file selection dialog. 2. Select the generated files. Locate and select GraphView.h and GraphView.cpp and click on OK. This adds the generated files to the files list in your Developer Studio project. Note that these generated files should already be in the same directory as the rest of the Developer Studio project. If they are not, then you will need to change project settings in the Developer Studio to include the files generated by DV-Draw. Adding #includes In order to use DataViews functionality in your application, you must include the appropriate header files in your application. 1. Add the header file to provide access to the Windows control functionality provided by DataViews. In MFCTutorialDlg.h, add the following line to the includes section: #include "DVMfcFramework.h"

19 Chapter 1: Deploying Your View in a Visual C++ Application 15 DVMfcFramework.h declares all the DataViews C++ classes and includes all the class header files. 2. Add the generated header file from the DataViews view. In MFCTutorialDlg.h, add the following line to the includes section: #include "GraphView.h" Adding Declarations The following instructions declare the member variables that are used for the DataViews interface within the custom control and the views that are to be displayed in that interface. In the MFCTutorialDlg.h header file, add the following protected member variables for the graph and view objects, the interface, and the view wrapper: CDVGraphHndl m_pdvgraphhndl; CDVViewHndl m_pdvviewhndl; CDVInterface *m_pdvinterface; CDVViewWrapper *m_pdvgraphview; In the GraphView.h header file, add the following protected member variable for the interface: CDVInterface *m_pdvinterface; Setting Up a Data Buffer for the Slider Control The tutorial application uses DataViews to display data residing in memory variables within the application. To handle this, we need to write code to connect this data to the data variables in the view. With the use of the MFC slider control to interact with the view s graph object, this tutorial demonstrates the concept of data buffer stuffing. In this technique, we stuff data into the buffer associated with the data variable. A detailed discussion of data buffer stuffing is beyond the scope of this book. For now, we will show you the steps in implementing the technique. For more information about handling data in your applications, see the on-line documentation.

20 16 DataViews Visual C++ Tutorial Guide In GraphView.h, add the following public member variable for the data buffer that the slider s data variable will use to update the graph: float *m_floatbufptr; //data buffer for the slider data variable Adding Initialization and Termination Code The following instructions add code to perform DataViews initialization and clean-up. 1. Add DataViews initialization code. In the CMFCTutorialApp::InitInstance() member function in MFCTutorial.cpp, insert the following line before the CMFCTutorialDlg dlg; line: CDVInterface::Initialize(); This line registers the custom control and initializes DataViews. 2. Add DataViews termination code. In the CMFCTutorialApp::ExitInstance() member function, add the following line before the return CWinApp::ExitInstance(); line: CDVInterface::Terminate(); This line cleans up the DataViews components of the application. Note that if your application does not already have an ExitInstance() member function on the application class, you have to use the ClassWizard in Visual C++ to create one.

21 Chapter 1: Deploying Your View in a Visual C++ Application 17 Adding Code to Attach the View The initialization section of MFCTutorialDlg.cpp is where you set up the custom control to display the view. This is where you make the connection between the DataViews view and the custom control that displays it. The CDVInterface instance is the glue between the view on the DataViews side of the application, and the custom control on the Windows side of the application: Windows (Microsoft Developer Studio) glue DataViews (DV-Draw) Custom Control CDVInterface View 1. Add code to attach a view. In the CMFCTutorialDlg::OnInitDialog() member function in MFCTutorialDlg.cpp, add the following lines after the TODO: Add extra initialization here line: CDVCustomControl *pwnd = (CDVCustomControl *) GetDlgItem(IDC_CUSTOM1); m_pdvinterface = pwnd->getdvinterface(); m_pdvgraphview = new CGraphView; m_pdvinterface->attachviewwrapper(m_pdvgraphview); m_pdvviewhndl= m_pdvinterface->getview(); m_pdvinterface->setautoupdate (TRUE); m_pdvinterface->setreaddataonupdate(true); The first line gets the custom control. Remember that IDC_CUSTOM1 is the ID of the custom control. The second line gets the DataViews interface from the custom control. The third line instantiates the view using the generated CGraphView class. The fourth line attaches the view to the custom control s interface. The next line retrieves the view from the interface. The last two lines ensure that dynamics are active. Adding Code to Detach and Destroy the View It is good practice to add code to detach and destroy the view when the application exits. In this example, we add a message handler to detach and destroy the view when the user clicks on the Quit button in the dialog.

22 18 DataViews Visual C++ Tutorial Guide Recall that the OK button was relabeled to Quit. Therefore, we add our view cleanup code to the OnOK() member function. 1. Define the OnOK() event handler member function. With the dialog-based application interface displayed in ResourceView of the Developer Studio, double-click on the Quit button to define an event handler. Since no event handler exists yet for the Quit button, this displays the Add Member Function dialog. Use the default settings and select OK to create an event handler for the Quit button and allow you to edit the handler code. 2. Add code to safely destroy DataViews views. In the CMFCTutorialDlg::OnOK() member function, insert the following lines before the CDialog::OnOK(); line: m_pdvinterface -> DetachViewWrapper(); delete m_pdvgraphview; Manipulating Objects Displayed in the Custom Control With the DataViews custom control in the Visual C++ dialog application, you can now add other controls to your dialog that act upon various characteristics of the objects in the DataViews views displayed by the control. In this tutorial, we will add the following functionality: Enter/edit the title for the graph displayed in the control. Change the number of data iterations displayed in the graph. Toggle between two different graph types. Stop/restart graph dynamics. Changing Object Properties 1. Add an Edit Box control to the dialog. Select the Edit Box control on the control palette in Developer Studio. Click and drag in the form, to the right of the custom control, to set the text edit box control s position and size. 2. Add a Static Text control to the dialog. Select the Static Text control on the control palette in Developer Studio. Click and drag in the form, above the Edit Box, to set the static text label control s position and size.

23 Chapter 1: Deploying Your View in a Visual C++ Application 19 Keep the control s ID as it is, but change the Caption property on the Static Text control to read Graph Title: You can edit the control s properties in Developer Studio by selecting the control and clicking the right mouse button to display the context menu. Choose the Properties... option to display the Edit Properties dialog for the control. 3. Add a member variable to the Edit Box control. Display the Developer Studio Class Wizard by selecting Class Wizard... under the View menu. Select the Member Variables tab of the Class Wizard dialog. Make sure the CMFCTutorialDlg class is selected in the Class Name combo box and select the IDC_EDIT1 control from the listing of the dialog s controls. Select the Add Variable... button to display the Add Member Variable dialog. Fill in the member variable name as m_graph_name, keeping the other default settings, and select the OK button. This member variable will hold the graph title. Select OK to dismiss the Class Wizard. 4. Add code to allow for the graph title to change. In the dialog editor view in Developer Studio, double click on the Edit Box control to display the Add Member Function dialog. Here you assign a particular message handler to a specific event. In this case, we want the Edit Box control to perform a procedure when the text in the control is changed. So we want to assign an EN_CHANGE event to the IDC_EDIT1 object. Select the OK button to add the empty message handler and allow you to add code. Insert the following lines of code into your OnChangeEdit1() method: void CMFCTutorialDlg::OnChangeEdit1() {... // TODO: Add your control notification handler code here } CEdit *pwnd = (CEdit *) GetDlgItem(IDC_EDIT1); pwnd->getwindowtext( m_graph_name ); m_pdvviewhndl = m_pdvinterface->getview(); m_pdvgraphhndl = m_pdvviewhndl.getobject("graph"); m_pdvgraphhndl.settitle(m_graph_name);

24 20 DataViews Visual C++ Tutorial Guide The first line retrieves the Edit Box control from the dialog, designated by the ID: IDC_EDIT1.TheGetWindowText() method retrieves the text from the edit box and assigns the data to the m_graph_name member variable. The next line of code obtains the view object handle from the interface using the GetView() method. Next, the graph object is retrieved from the view object using the CDVViewHndl::GetObject() method. Specific objects in our view have been provided names. In this particular line of code, the GetObject() method gets the object in the view with the name graph. The final line uses the CDVGraphHndl::SetTitle() method to assign the Title Property of the graph object to the information set in the edit box control. That means that when the user enters or changes text in the text field, the information is displayed in the graph as the graph title. Changing the Number of Data Iterations 1. Add another Edit Box control to the dialog. Add a second Edit Box control to the dialog. 2. Add another Static Text control to the dialog. Add a second static text control and change the Caption property to read: Number of Data Iterations: 3. Add a member variable to the Edit Box control. As with the first Edit Box control, use the Class Wizard to add a member variable that represents the number of data iterations entered into the control. In the Member Variables tab of the Class Wizard, select the IDC_EDIT2 control from the listing of the dialog s controls. Select the Add Variable... button to display the Add Member Variable dialog. Fill in the member variable name as m_data_num, keeping the other default settings, and select the OK button to dismiss the Add Member Variable dialog. This member variable will hold a string representing the number of data iterations. Select OK to dismiss the Class Wizard. 4. Add a Button control to the dialog. Select the Button control on the control palette in Developer Studio. Click and drag in the form, to the right of the new edit box, to set the command button control s position and size. Change the Caption property on the IDC_BUTTON1 control to read Apply.

25 Chapter 1: Deploying Your View in a Visual C++ Application Add code to apply the number of data iterations to the graph. Double click on the Button control to display Add Member Function dialog. As with the first Edit Box control, we want to assign an event to the new Button control. In this case, we want to add a BN_CLICKED event handler to the button control. Select the OK button to add the empty message handler and allow you to add code. This specific event handler will hold code that is executed when the user selects the button in the dialog. Insert the following lines of code into your OnButton1() method: void CMFCTutorialDlg::OnButton1() { // TODO: Add your control notification handler code here } CEdit *pwnd = (CEdit *) GetDlgItem(IDC_EDIT2); pwnd->getwindowtext( m_data_num ); int data = atoi(m_data_num); m_pdvviewhndl = m_pdvinterface->getview(); m_pdvgraphhndl = m_pdvviewhndl.getobject("graph"); m_pdvgraphhndl.setnumslots(data); As with the first Edit Box, the first line retrieves the Edit Box control from the dialog, designated here by the ID: IDC_EDIT2 The GetWindowText() method retrieves the text from the edit box and assigns the data to the m_data_num member variable, which then is assigned to the integer variable data. The next two lines of code perform the same functions as with the first Edit Box control: first, the view object is retrieved from the interface, then the object named graph is obtained from the view. The final line uses the CDVGraphHndl::SetNumSlots() method to assign the NumSlots Property of the graph object to the information set in the edit box control. That means that when the user enters or changes text in the text field, and selects the Apply button, the number of data iterations changes. Changing the Object Type 1. Add two Radio Button controls to the dialog. Select the Radio Button control on the control palette in Developer Studio. Click and drag in the form, to the right of the custom control, to set the option button control s position and size.

26 22 DataViews Visual C++ Tutorial Guide Repeat the procedure to add a second radio button control below the first. Change their Caption properties so that the IDC_RADIO1 control has a Caption property of Bar Graph while the IDC_RADIO2 control has a Caption property of Strip Graph. 2. Add code to swap between graph types. Double click on the IDC_RADIO1 control and add a BN_CLICKED event handler to the first radio button control. Add the following code to your OnRadio1() method: void CMFCTutorialDlg::OnRadio1() { m_pdvviewhndl = m_pdvinterface->getview(); m_pdvgraphhndl = m_pdvviewhndl.getobject("graph"); m_pdvgraphhndl.setgraphtype(dv_graph_type_bar); } This code is similar to the code for the other controls we have placed in the form. The graph object properties are accessed through the view object attached through the custom control. In this procedure, the GraphType Property on the CDVGraphHndl class is assigned a new value: that of a bar graph. When a user selects this option in the Visual C++ application, the graph displayed by the control changes from a strip graph to a bar graph. In order to allow the user to revert to the original graph type, we added the following code to the OnRadio2() method: void CMFCTutorialDlg::OnRadio2() { m_pdvviewhndl = m_pdvinterface->getview(); m_pdvgraphhndl = m_pdvviewhndl.getobject("graph"); m_pdvgraphhndl.setgraphtype(dv_graph_type_strip); } Here the graph type is assigned to be a strip graph, which was its original type. The DV_GRAPH_TYPE_BAR and DV_GRAPH_TYPE_STRIP assignments represent enumerated types that DataViews can interpret internally as different types of graphs. For more information concerning DataViews C++ objects, such as CDVGraphHndl, CDVViewHndl, and DataViews enumerated types, see the DataViews C++ Reference Manual.

27 Chapter 1: Deploying Your View in a Visual C++ Application 23 Stopping/Restarting View Dynamics 1. Add two Button controls to the dialog. Select the Button control on the control palette in Developer Studio. Click and drag in the form, to the right of the custom control, to set the command button control s position and size. Repeat the procedure to add a second command button control below the first. Change their Caption properties so that the IDC_BUTTON2 control has a Caption property of Stop Dynamics while the IDC_BUTTON3 control hasa Caption property of Start Dynamics. 2. Addcodetostartandstopdynamics. Double click on the IDC_BUTTON2 control to add a BN_CLICKED event handler to the button control. Add the following code to your OnButton2() method: void CMFCTutorialDlg::OnButton2() { m_pdvinterface->setautoupdate (FALSE); m_pdvinterface->setreaddataonupdate(false); CWnd *pwnd = (CWnd *) GetDlgItem(IDC_BUTTON2); pwnd->enablewindow(false); CWnd *pwnd_new = (CWnd *) GetDlgItem(IDC_BUTTON3); pwnd_new->enablewindow(); } This code turns off the DVPlayer control s ability to automatically update objects by setting the AutoUpdate boolean flag to FALSE. The Start Dynamics button is enabled and the Stop Dynamics button is disabled.

28 24 DataViews Visual C++ Tutorial Guide Double click on the IDC_BUTTON3 control to add a BN_CLICKED event handler to the button control. Add the following code to your OnButton3() method: void CMFCTutorialDlg::OnButton3() { m_pdvinterface->setautoupdate (TRUE); m_pdvinterface->setreaddataonupdate(true); CWnd *pwnd = (CWnd *) GetDlgItem(IDC_BUTTON3); pwnd->enablewindow(false); CWnd *pwnd_new = (CWnd *) GetDlgItem(IDC_BUTTON2); pwnd_new->enablewindow(true); } This code turns on the DVPlayer control s ability to automatically update objects by setting the AutoUpdate boolean flag to TRUE. The Stop Dynamics button is enabled and the Start Dynamics button is disabled. Handling the Rule Events on the View Earlier in this tutorial, we generated the OnAfterAttach() and OnHorizontalScroll() event handlers after we created two corresponding rule events on the view. In this section, we apply code to these event handlers so that we may use the MFC slider control to manipulate and display data in the graph. Getting the Data Buffer Address for the Slider Control Recall that the slider uses a memory data source called default.mem and uses the data variable called slider. The actual buffer address is retrieved in the AfterAttach() event handler. To get the address, we supply the name of the data source and the data variable. Add the following code to your OnAfterAttach() method in GraphView.cpp: void CGraphView::OnAfterAttach() { m_pdvinterface = GetDVInterface(); CDVDataVarHndl dvh =m_pdvinterface-> GetDataVar("default.mem","slider"); if (dvh.getisvalid()) m_floatbufptr = (float*) dvh.getbuffer(); CSliderCtrl *hslider = (CSliderCtrl *)m_pdvinterface-> GetDlgItem(IDC_SLIDER1); hslider->setrange(0,100); }

29 Chapter 1: Deploying Your View in a Visual C++ Application 25 The interface is initially retrieved, while GetDataVar() returns the specified data variable. The GetBuffer() method then retrieves the data buffer. The data buffer is assigned to the data buffer variable m_floatbufptr. The slider control is also retrieved from the view (using the default name IDC_SLIDER1) and its range is set to be from 0 to 100. Moving the Data From the Buffer to the Graph Now that the application knows the address of the data buffer, we can use the OnHorizontalScroll() event handler to fill the data buffer and display the new data in the graph. void CGraphView::OnHorizontalScroll(UINT nsbcode, UINT npos, CScrollBar* pscrollbar) { float scroll_position; scroll_position = (float)((csliderctrl *)pscrollbar)->getpos(); *m_floatbufptr = (scroll_position/100); CDVObjectHndl bargraph = GetNamedObject("graph"); bargraph.drawnext(); } We retrieve the position of the slider and normalize the value to account for the graph s range of data and to provide smoother data. We assign the normalized value to the buffer variable m_floatbufptr. The rest of the code retrieves and redraws the object named graph. Building and Running the Application Now that you have completed coding your new application, you can now prepare to build and run the application. Including the DataViews Header Files The application includes various DataViews files, so you must tell Developer Studio wheretofindthem.notethat<dataviews> denotes the directory where DataViews is installed on your computer. 1. Open the Options dialog. Pull down the Tools menu and select Options. Proceed to the Directories tab. In the Show directories for field, make sure Include files is selected. Go to the bottom of the list of directories and click in the empty field.

30 26 DataViews Visual C++ Tutorial Guide 2. Add the DataViews header files. Enter the full directory paths for the include files, or click on the ellipsis button to display the navigator and navigate to the <dataviews>\include\ directory. Close the dialog when you have finished. Including the DataViews Libraries You must also tell Developer Studio where to find the link files. 1. Open the Options dialog. Pull down the Tools menu and select Options. Proceed to the Directories tab. In the Show directories for field, make sure Library files is selected. Go to the bottom of the list of directories and click in the empty field. 2. Add the DataViews library files. Enter the full directory paths for the include files, or click on the ellipsis button to display the navigator and navigate to the <dataviews>\lib\ directory. Close the dialog when you are finished. Including the DataViews System Libraries You must also tell Developer Studio where to find the DataViews executable files. 1. Open the Options dialog. Pull down the Tools menu and select Options. Proceed to the Directories tab. In the Show directories for field, make sure Executable files is selected. Go to the bottom of the list of directories and click in the empty field. 2. Add the DataViews system library files. Enter the full directory paths for the include files, or click on the ellipsis button to display the navigator and navigate to the <dataviews>\system\ directory. Close the dialog when you are finished.

31 Chapter 1: Deploying Your View in a Visual C++ Application 27 Linking to the DataViews Libraries Building the application also links to required files, so you must tell Developer Studio what files to link in. 1. Open the Settings dialog. Pull down the Project menu and select Settings. Proceed to the Link tab. 2. Add the DataViews libraries. In the Object/library modules field, make sure the following file names are listed: dvwind.lib DVtoolsd.lib DVnamesd.lib Note that these are the debug versions. The default is to use the debug versions. The release versions of these files would be: dvwin.lib DVtools.lib DVnames.lib Dismiss the dialog when you are finished. Building and Running the Application 1. Save your work. Select the Save Workspace option under the File menu to save your work in Developer Studio. 2. Build the application. Pull down the Build menu and select Build MFCTutorial.exe. 3. Run the application. Pull down the Build menu and select Execute MFCTutorial.exe.

32 28 DataViews Visual C++ Tutorial Guide Your application should be similar to the following figure: 1. Assign a text string to be the graph s title. Type a text string in the Graph Title text box and view the text as the graph s title. 2. Change the number of data iterations. Type a numerical value in the Number of Data Iterations text box. Select the Apply button and watch the graph s data display change. 3. Change the type of graph. Select the Bar Graph radio button to change the type of graph from a strip graph to a bar graph. Click on the Strip Graph radio button to return the graph to its original type. 4. Stop/start dynamics. Select the Stop Dynamics button to halt automatic updating of data in the graph. Select Start Dynamics to resume data update. 5. Change slider values. Click the slider control and see the data change in the graph.

33 Chapter 1: Deploying Your View in a Visual C++ Application 29 For More Information This tutorial only touches upon a few of the many DataViews objects you can create andmanageinvisualc++usingthecdvcustomcontrol class. The graph object is actually one of many objects in the DataViews C++ class library that you have access to in Visual C++. The library consists of many graphical objects, such as graphs, circles, and polygons, as well as non-graphical objects, such as dynamics, thresholds, and graph variable descriptors. For more information on using the DataViews C++ class library, see the DataViews Visual C++ Application Developer s Guide. Topics include: Application Development Model Provides general information for programming with DataViews in Visual C++. DataViews C++ Library Overview Presents an overview of the data structures of the DataViews C++ class library including views, graphical objects, data sources, and dynamics structures. Working With Graphical Objects Discusses how you can programmatically create and manipulate graphical objects using the DataViews C++ class library. Working With Graphs Describes how to programmatically access a DataViews graph s data structures, how to set a graph s characteristics, and how to obtain information about your graphs using the DataViews C++ class library. Handling Data Describes handling data in your applications through the DataViews C++ class library using data sources and data variables. Programming Object Dynamics Discusses implementing object dynamics using the DataViews C++ class library. For more information on DataViews C++ programming issues, please refer to the DataViews Visual C++ Programming Topics in the on-line documentation. Topics include: Programming a ScrollView Application Demonstrates how to use DataViews views that contain Windows controls in a ScrollView application. The example is created using Microsoft Developer Studio.

34 30 DataViews Visual C++ Tutorial Guide DataViews Event Handlers Discusses what kinds of code can be implemented at various points in the application by using DataViews event handlers. Subclassing View Wrappers Demonstrates how to use generic DataViews views that do not contain Windows controls in an application. The example is created using Microsoft Developer Studio. Refining the View Discusses how to control various common aspects of the view s appearance and behavior, and how to control the generation of Click and InputUsed events. To learn more about the DataViews C++ classes and their various methods, and properties, see the The DataViews C++ Classes in the DataViews Visual C++ Reference Manual. For more information about using DV-Draw to build data-driven dynamic views, please refer to the DV-Draw Help Topics in the on-line documentation. You should also study the various demos and examples provided with the release.

35 31 Index A AfterAttach() 24 application development building and running in Visual C++ 25 AutoUpdate Property 23 C CDVCustomControl 3, 13 CDVInterface 17 code generation 10 controls adding Windows controls to a DataViews view 5 custom control adding to dialog 13 D data changing iterations in graphs 20 connection 15 data source adding to a graph 7 dialog-based applications 3 DV-Draw generating C++ code 10 dynamics starting and stopping in C++ 23 E events handling in a C++ application 5, 24 OnAfterAttach() 24 OnHorizontalScroll() 25 G GetBuffer() 25 GetDataVar() 25 GetObject() 20 GetView() 20 graph adding a data source 7 changing the number of data iterations 20 setting a new graph type 21 setting the title 18 O OnAfterAttach() 5, 9 OnHorizontalScroll() 5, 9, 25 R rules adding to a DataViews view 5, 9 S SetNumSlots() 21 SetTitle() 20 V view adding Windows controls 5 detaching and destroying 17 displaying in a dialog application 11 initialization and termination 16 Visual C++ building and running applications 25 tutorial example 3 W Windows controls adding to a DataViews view 5

36