FileSelector.java

package org.iplantc.de.client.views;

import org.iplantc.de.client.ClientAction;
import org.iplantc.de.client.I18N;
import org.iplantc.de.client.models.File;
import org.iplantc.de.client.views.dialogs.FileSelectDialog;
import org.iplantc.de.client.views.dialogs.IPlantDialog.DialogOkClickHandler;

import com.extjs.gxt.ui.client.event.BaseEvent;
import com.extjs.gxt.ui.client.event.ButtonEvent;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.event.Listener;
import com.extjs.gxt.ui.client.widget.Composite;
import com.extjs.gxt.ui.client.widget.HorizontalPanel;
import com.extjs.gxt.ui.client.widget.button.Button;
import com.extjs.gxt.ui.client.widget.form.TextField;

/**
 * Models a composite widget for selecting a file from a user's workspace. 
 * 
 * @author lenards
 * 
 */
public class FileSelector extends Composite
{
	public static final String CALLER_TAG = "file_select_";
	
	public static final String DEFAULT_WIDTH = "620px";
	// TODO: i18n this caption...
	public static final String DEFAULT_CAPTION = "Select a file";

	/**
	 * Shared counter to create identifiers for the calling instance.
	 */
	private static int CallerTagCount = 0;
	
	private String tag;
	private HorizontalPanel composite = new HorizontalPanel();
	private Button btnLaunch;
	private FileSelectDialog dlgFileSelect;
	protected File selectedFile;
	protected TextField<String> txtFilename;
	protected ClientAction actionChange;

	/**
	 * 
	 */
	public FileSelector()
	{
		this(null);	
	}
	
	/**
	 * 
	 */
	public FileSelector(ClientAction actionChange)
	{
		this.actionChange = actionChange;
		initComponent(composite);
		initWidgets();
	}	
	
	protected void initWidgets()
	{
		tag = createTag();
		
		composite.setSpacing(9);
		
		txtFilename = new TextField<String>();
		txtFilename.setId("idFileName");
		txtFilename.setReadOnly(true);
		txtFilename.setPosition(-9, 0);
		txtFilename.setWidth(254);
		
		btnLaunch = new Button(I18N.DISPLAY.browse());
		btnLaunch.setId("idBtnLaunch");
		btnLaunch.addListener(Events.OnClick, new Listener<BaseEvent>()
		{
			public void handleEvent(BaseEvent be)
			{
				dlgFileSelect = new FileSelectDialog(tag, DEFAULT_CAPTION);
				dlgFileSelect.addOkClickHandler(new DialogOkClickHandler()
				{
					@Override
					public void componentSelected(ButtonEvent ce)
					{
						setSelectedFile(dlgFileSelect.getSelectedFile());
						txtFilename.setValue((selectedFile == null) ? "" : selectedFile.getName());
						
						if(actionChange != null)
						{
							actionChange.execute();
						}
					}
				});				
				dlgFileSelect.show();	
			}
		});
	
		btnLaunch.focus();
		
		composite.add(txtFilename);
		composite.add(btnLaunch);
	}
	
	private String createTag()
	{
		return CALLER_TAG + CallerTagCount++;
	}

	/**
	 * Indicates if the widget has a selected file.
	 * 
	 * @return true, if there is a selection; otherwise false.
	 */
	public boolean hasSelectedFile()
	{
		return selectedFile != null;
	}

	/**
	 * Retrieves the selected file.
	 * 
	 * This will return null when a file is not selected.
	 * 
	 * @return a reference to the selected file or null when there is no selection.
	 */
	public File getSelectedFile()
	{
		return selectedFile;
	}

	/**
	 * Defines the selected file.
	 *
	 * This will all set the selected file in the underlying widgets (including the
	 * FileSelectDialog)
	 *
	 * @param file the selected file
	 */
	public void setSelectedFile(File file)
	{
		dlgFileSelect.select(file);
		selectedFile = file;
	}

	/**
	 * Retrieves an identifier for the file that can be used to fetch metadata or content.
	 * 
	 * This will return null when a file is not selected.
	 * 
	 * @return a string representing the identifier for the selected file or null when
	 *         there is no selection.
	 */
	public String getSelectedFileId()
	{
		return hasSelectedFile() ? selectedFile.getId() : null;
	}

	/**
	 * Sets the internal spacing on the widget's root panel.
	 * 
	 * @param spacing an integer representing the spacing to use
	 */
	public void setSpacing(int spacing)
	{
		composite.setSpacing(spacing);
	}

	/**
	 * Sets the caption, or title , of the file selection dialog.
	 * 
	 * @param caption
	 */
	public void setDialogCaption(String caption)
	{
		dlgFileSelect.setCaption(caption);
	}

	/**
	 * Sets the text for the button used to launch the file selection dialog.
	 * 
	 * @param text
	 */
	public void setButtonText(String text)
	{
		btnLaunch.setText(text);
	}

	public void setTextFieldPosition(int left, int top)
	{
		txtFilename.setPosition(left, top);
	}
	
	public void displayFilename(String name)
	{
		txtFilename.setValue(name);
	}
}