package org.eclipse.ui.tests.api.workbenchpart;

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.internal.WorkbenchPlugin;
import org.eclipse.ui.part.ViewPart;
import org.eclipse.ui.tests.TestPlugin;

public class HeavyResourceView extends ViewPart {

    private Button useAllComposites;
    private Button releaseAllComposites;
    
    private Shell tempShell;
    private Composite control;
    
    public void createPartControl(Composite parent) {
        control = parent;
        
        SelectionListener listener = new SelectionAdapter() {
          public void widgetSelected(SelectionEvent e) {
                super.widgetSelected(e);
                
                if (e.widget == useAllComposites) {
                    useAll();
                } else if (e.widget == releaseAllComposites) {
                    releaseAll();
                }
            }  
        };
        
        Label explanation = new Label(parent, SWT.WRAP);
        explanation.setText("This view allocates all available SWT resources on demand. " 
                + "This is not supposed to be a recoverable error, and is expected to crash the workbench. "
                + "This view allows us observe the workbench when it crashes in this manner.");
        
        useAllComposites = new Button(parent, SWT.PUSH);
        useAllComposites.setText("&Allocate all available composites (very slow!)");
        useAllComposites.addSelectionListener(listener);
        
        releaseAllComposites = new Button(parent, SWT.PUSH);
        releaseAllComposites.setText("&Release all composites");
        releaseAllComposites.addSelectionListener(listener);
           
    }

    public void setFocus() {
        control.setFocus();
    }
    
    public void useAll() {
        releaseAll();
        tempShell = new Shell(Display.getCurrent(), SWT.NONE);
        int count = 0;
        try {
            for(;;) {
                Composite next = new Composite(tempShell, SWT.NONE);
                count++;
            }
        } catch (SWTError e) {
            TestPlugin.getDefault().getLog().log(WorkbenchPlugin.getStatus(e));
        }
    }
    
    public void releaseAll() {
        if (tempShell != null) {
            tempShell.dispose();
            tempShell = null;
        }
    }
    
    public void dispose() {
        releaseAll();
        super.dispose();
    }

}