SWT Browser and Image Capture

Recently I was playing with the SWT-COM bridge and its Win32 APIs. Believe me or not, but the SWT Browser is the best SWT based UI control I have seen (you can argue but without any success). 

One of the experimental feature I tried accomplishing was to print the full HTML page as Image, and the result was superb !!

See the below images for the embedded browser control and the output of the image capturing utility !! Cool right ;)

Modified Browser Control:

Captured Image:

Atlapp and secure atl !!

After upgrading to VS2008, I started getting errors for lstrlenA, size_t, and lstrcpynA. My "include directories" settings are exactly the same as my old VS2005, and if I open the project in VS2005, everything compiles just fine. So what is the fix for this problem??

And the fix is really simple, before including atlapp.h, just define:

#define _SECURE_ATL 1 

SWT - Capturing Control Screen-Shot

SWT code for capturing control screen-shot.

public class ScreenCaptureTest 
{
 public static void main(String[] args) 
 {
  String[] names  = {"Harry", "Sally", "Jhon", "Tim", "Scott"};
  String[] msg = {"Hello World!", "Today is a nice day to walk", "I am bored", "This is how you take widget capture", "Ha Ha Ha!! That's funny !"}; 
  
  final Display display = new Display();
  final Shell shell = new Shell(display);
  shell.setText("Screen Capture");
  shell.setLayout(new GridLayout(1, true));
  
  final Composite composite = new Composite(shell, SWT.BORDER);
  composite.setLayout(new GridLayout(2, true));
  composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
  
  Table table = new Table(composite, SWT.BORDER|SWT.V_SCROLL|SWT.H_SCROLL|SWT.FULL_SELECTION);
  
  table.setLinesVisible(true);
  table.setHeaderVisible(true);
  
  table.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
  
  TableColumn columnName = new TableColumn(table, SWT.LEFT);
  columnName.setText("Name");
  columnName.setWidth(100);
  
  TableColumn columnMsg = new TableColumn(table, SWT.LEFT);
  columnMsg.setText("Message");
  columnMsg.setWidth(200);
  
  for (int i = 0; i < 5; i++) 
  {
   TableItem item = new TableItem(table, SWT.NONE, 0);
   item.setText(0, names[i]);
   item.setText(1, msg[i]);   
  }
  
  StyledText text = new StyledText (composite, SWT.BORDER);
  text.setText("0123456789 ABCDEFGHIJKLM NOPQRSTUVWXYZ");
  text.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
  
  StyleRange style1 = new StyleRange();
  style1.start = 0;
  style1.length = 10;
  style1.fontStyle = SWT.BOLD;
  text.setStyleRange(style1);
  
  StyleRange style2 = new StyleRange();
  style2.start = 11;
  style2.length = 13;
  style2.foreground = display.getSystemColor(SWT.COLOR_RED);
  text.setStyleRange(style2);
  
  StyleRange style3 = new StyleRange();
  style3.start = 25;
  style3.length = 13;
  style3.background = display.getSystemColor(SWT.COLOR_BLUE);
  text.setStyleRange(style3);
  
  Button button = new Button(shell, SWT.PUSH);
  button.setText("Capture");
  button.pack();

  button.addListener(SWT.Selection, new Listener()
  {
   public void handleEvent(Event event) 
   {
    GC gc = new GC(display);
    final Image image = new Image(display, shell.getBounds());
    gc.copyArea(image, shell.getBounds().x, shell.getBounds().y);
    gc.dispose();

    Shell popup = new Shell(shell);
    popup.setText("Captured Image");
    popup.addListener(SWT.Close, new Listener() {
     public void handleEvent(Event e) {
      image.dispose();
     }
    });

    Canvas canvas = new Canvas(popup, SWT.NONE);
    canvas.setBounds(0,0,image.getImageData().width, image.getImageData().height);
    canvas.addPaintListener(new PaintListener() {
     public void paintControl(PaintEvent e) {
      e.gc.drawImage(image, 0, 0);
     }
    });
    popup.pack();
    popup.open();
   }
  });
  
  shell.pack();
  shell.open();
  
  while (!shell.isDisposed()) {
   if (!display.readAndDispatch())
    display.sleep();
  }
  
  display.dispose();
 }
}

Original Composite:

Captured Image:

Programmatically create eclipse Java project

Following is a brief code snippet for creating an eclipse Java project using core JDT API.

private IJavaProject createProject() throws Exception
{
    IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
    String projName = getProjectName();

    if(projName == null || projName.trim().length() == 0)
        return null;

    //create eclipse project
    IProject project = root.getProject(projName);
    if(project.exists())
        project.delete(true, null);

    project.create(null);
    project.open(null);

    //set the java project nature
    IProjectDescription description = project.getDescription();
    description.setNatureIds(new String[] { JavaCore.NATURE_ID});
    project.setDescription(description, null);

    //create java project
    IJavaProject javaProject = JavaCore.create(project);

    //add bin/ouput folder
    IFolder binFolder = project.getFolder("bin");
    binFolder.create(false, true, null);
    javaProject.setOutputLocation(binFolder.getFullPath(), null);

    //add libs to project class path
    List<IClasspathEntry> entries = new ArrayList<IClasspathEntry>();
    IVMInstall vmInstall = JavaRuntime.getDefaultVMInstall();
    LibraryLocation[] locations = JavaRuntime.getLibraryLocations(vmInstall);
    for (LibraryLocation element : locations) {
        entries.add(JavaCore.newLibraryEntry(element.getSystemLibraryPath(), null, null));
    }
    
    javaProject.setRawClasspath(entries.toArray(new IClasspathEntry[entries.size()]), null);

    //create source folder
    IFolder sourceFolder = project.getFolder("src");
    sourceFolder.create(false, true, null);

    IPackageFragmentRoot srcRoot = project.getPackageFragmentRoot(sourceFolder);
    IClasspathEntry[] oldEntries = project.getRawClasspath();
    IClasspathEntry[] newEntries = new IClasspathEntry[oldEntries.length + 1];
    System.arraycopy(oldEntries, 0, newEntries, 0, oldEntries.length);
    newEntries[oldEntries.length] = JavaCore.newSourceEntry(srcRoot.getPath());
    project.setRawClasspath(newEntries, null);

    return javaProject;
}

private String getProjectName()
{
    String init_value = "project_" + System.currentTimeMillis();
    InputDialog dialog = new InputDialog(getShell(), "Java Project", "Provide project name ..", init_value, new IInputValidator() {
        public String isValid(String newText)
        {
            char[] array = newText.toCharArray();
            for (int i = 0; i < array.length; i++)
            {
                if(!Character.isJavaIdentifierPart(array[i]))
                    return "Cannot contain special characters !!";
            }

            IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
            IProject[] projs = root.getProjects();
            for (int i = 0; i < projs.length; i++) {
                if(projs[i].getName().equalsIgnoreCase(newText))
                    return "Project already exist !!";
            }

            /*
                Not checking for special Win32 names like con etc.
            */
            return null;
        }
    });

    if(dialog.open() == Dialog.CANCEL)
        return null;

    return dialog.getValue();
}

Running PostgreSQL From Command Line

This October I enrolled for the online database course offered by Stanford university. I started out with SQLite as the RDBMS of my choice because it is easy to use, needs no installation and one can use it out of the box. But, in case of SQLite simplicity was the main problem too. So, I downloaded the PostgreSQL for windows. Now, as my workstation is normally overloaded (so I can’t afford background services) and also I just wanted to have a no-install distribution; so I downloaded the Zip Archive.

The first problem I faced was that when I started to run my postgres server then it gave me this long error message:

“Execution of PostgreSQL by a user with administrative permissions is not permitted.The server must be started under an unprivileged user ID to prevent possible system security compromises.  See the documentation for more information on how to properly start the server.”

Forums were of no use and mostly people were suggesting to create a non-admin user and use it. But the problem is I can’t do that as I am working a system which doesn’t allow me to do that. So, I read the documentation and found pg_ctl which is a utility to initialize, start, stop, or control a PostgreSQL server. Here are the steps:

1. CD C:\pgsql\bin (or where ever your postgres bin folder is)
2. set PGDATA=c:/temp/test
3. pg_ctl.exe init
   The files belonging to this database system will be owned by user "ABCDXYZ". This user must also own the server process….
4. Although after the step# 2 it instructs to start your postgres server as "C:/pgsql/bin\postgres" -D "c:/temp/test"; but it is of no use. Instead do this, pg_ctl.exe start
5. That it, the server is running and the process is owned by the logged in user.
6. Now for the admin tool, run the ‘pgAdmin3.exe’ (its inside the C:\pgsql\bin)
7. Now select ‘Add a connection to server’ toolbar button. This will show an image like this and fill in the values as suggested:
   

   

   
   
8. Finally this page will come: