Bug 309899 - New local terminal launch configurations should have reasonable default values

releng/org.eclipse.rse.build/maps/terminal.map

@@ -7,7 +7,7 @@ feature@org.eclipse.tm.terminal.telnet=v201005032000,:pserver:anonymous:none@dev
 feature@org.eclipse.tm.terminal.test=v200905272300,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.test-feature
 feature@org.eclipse.tm.terminal.view=v201005032000,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.view-feature
 plugin@org.eclipse.tm.terminal=v201005200200,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal
-plugin@org.eclipse.tm.terminal.local=v201005032000,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.local
+plugin@org.eclipse.tm.terminal.local=v201005200200,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.local
 plugin@org.eclipse.tm.terminal.serial=v200905272300,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.serial
 plugin@org.eclipse.tm.terminal.ssh=v200905272300,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.ssh
 plugin@org.eclipse.tm.terminal.telnet=v200909160005,:pserver:anonymous:none@dev.eclipse.org:/cvsroot/dsdp,,org.eclipse.tm.core/terminal/org.eclipse.tm.terminal.telnet

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalConnector.java

@@ -13,7 +13,12 @@
 package org.eclipse.tm.internal.terminal.local;
 
 import java.io.OutputStream;
+import java.text.Format;
+import java.text.MessageFormat;
+
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
 import org.eclipse.debug.core.DebugEvent;
 import org.eclipse.debug.core.DebugException;
 import org.eclipse.debug.core.DebugPlugin;
@@ -26,6 +31,9 @@ import org.eclipse.debug.core.model.IProcess;
 import org.eclipse.debug.core.model.IStreamMonitor;
 import org.eclipse.debug.core.model.IStreamsProxy;
 import org.eclipse.debug.ui.IDebugUIConstants;
+import org.eclipse.jface.dialogs.ErrorDialog;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
 import org.eclipse.tm.internal.terminal.local.launch.LocalTerminalLaunchUtilities;
 import org.eclipse.tm.internal.terminal.local.process.LocalTerminalProcessFactory;
 import org.eclipse.tm.internal.terminal.local.process.LocalTerminalProcessRegistry;
@@ -42,7 +50,7 @@ import org.eclipse.tm.internal.terminal.provisional.api.provider.TerminalConnect
  * <code>vi</code> editor).
  *
  * @author Mirko Raner
- * @version $Revision: 1.4 $
+ * @version $Revision: 1.1 $
  */
 public class LocalTerminalConnector extends TerminalConnectorImpl
 implements IDebugEventSetListener {
@@ -171,22 +179,48 @@ implements IDebugEventSetListener {
 		control.setState(TerminalState.CONNECTING);
 		ILaunchConfigurationWorkingCopy workingCopy = null;
 		ILaunchConfiguration configuration = null;
+		String configurationName = null;
 		try {
 
-			String configurationName = settings.getLaunchConfigurationName();
+			configurationName = settings.getLaunchConfigurationName();
 			configuration = LocalTerminalUtilities.findLaunchConfiguration(configurationName);
+		}
+		catch (CoreException exception) {
 
-			// Always set the the process factory ID and enable console output (there is no need
+			Shell shell = Display.getDefault().getActiveShell();
-			// to restore these attributes afterwards; disabling console output does not make
+			String title = LocalTerminalMessages.errorTitleCouldNotConnectToTerminal;
-			// sense for terminal launches and will be overridden when the configuration is
+			Format text;
-			// actually launched):
+			text = new MessageFormat(LocalTerminalMessages.errorLaunchConfigurationNoLongerExists);
-			//
+			String message = text.format(new Object[] {configurationName});
+			IStatus status = new Status(IStatus.ERROR, LocalTerminalActivator.PLUGIN_ID, message);
+			ErrorDialog.openError(shell, title, null, status);
+			control.setState(TerminalState.CLOSED);
+			return;
+		}
+		try {
+
+			String oldFactoryID = configuration.getAttribute(ATTR_PROCESS_FACTORY_ID, (String)null);
 			workingCopy = configuration.getWorkingCopy();
 			workingCopy.setAttribute(ATTR_CAPTURE_OUTPUT, true);
 			workingCopy.setAttribute(ATTR_CAPTURE_IN_CONSOLE, true);
 			workingCopy.setAttribute(ATTR_PROCESS_FACTORY_ID, LocalTerminalProcessFactory.ID);
 			configuration = workingCopy.doSave();
+			try {
+
 				launch = configuration.launch(ILaunchManager.RUN_MODE, null);
+			}
+			finally {
+
+				// The process factory ID is used to distinguish between launches that originate
+				// from the terminal connector and launches that originate from the launch dialog.
+				// After launching, the original ID is restored so that the launch is not mistaken
+				// as originating from the terminal connector UI when it is launched via the launch
+				// dialog the next time:
+				//
+				workingCopy = configuration.getWorkingCopy();
+				workingCopy.setAttribute(ATTR_PROCESS_FACTORY_ID, oldFactoryID);
+				workingCopy.doSave();
+			}
 
 			// To prevent a console from being allocated, the launch will actually not contain a
 			// reference to the runtime process. The process has to be obtained from the
@@ -257,9 +291,9 @@ implements IDebugEventSetListener {
 			//
 			LocalTerminalProcessRegistry.addProcessBackToFinishedLaunch(launch);
 
-			// Now, terminate the process if it hasn't been terminated already:
+			// Now, terminate the process if it was ever started and hasn't been terminated already:
 			//
-			if (launch.canTerminate()) {
+			if (launch != null && launch.canTerminate()) {
 
 				launch.terminate();
 				//

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalLaunchListProvider.java

@@ -51,7 +51,7 @@ public class LocalTerminalLaunchListProvider implements IStructuredContentProvid
 	public Object[] getElements(Object input) {
 
 		ILaunchManager launchManager = DebugPlugin.getDefault().getLaunchManager();
-		ILaunchConfigurationType type = LocalTerminalUtilities.PROGRAM_LAUNCH_TYPE;
+		ILaunchConfigurationType type = LocalTerminalUtilities.TERMINAL_LAUNCH_TYPE;
 		ILaunchConfiguration[] configurations = null;
 		try {
 

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalMessages.java

@@ -18,7 +18,7 @@ import org.eclipse.osgi.util.NLS;
  * messages used by the Local Terminal Connector.
  *
  * @author Mirko Raner
- * @version $Revision: 1.3 $
+ * @version $Revision: 1.1 $
  */
 public class LocalTerminalMessages extends NLS {
 
@@ -80,6 +80,15 @@ public class LocalTerminalMessages extends NLS {
 	/** The error message for an invalid working directory location. */
 	public static String invalidWorkingDirectory;
 
+	/** The error message for attempting to directly launch a Terminal launch configuration. */
+	public static String errorDirectLaunch;
+
+	/** The error message for attempting to launch a no longer existing launch configuration. */
+	public static String errorLaunchConfigurationNoLongerExists;
+
+	/** The error dialog title for failed terminal connections. */
+	public static String errorTitleCouldNotConnectToTerminal;
+
 	/** The title string of the warning displayed when terminal launches are still running. */
 	public static String warningTitleTerminalsStillRunning;
 

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalMessages.properties

@@ -28,6 +28,13 @@ locationNotSpecified=Executable location was not specified in configuration ''{0
 invalidLocation=Executable does not exist for the external tool named ''{0}''
 invalidWorkingDirectory=The path {0} is not a directory and cannot be used as working directory \
  for ''{1}''
+errorDirectLaunch=Terminal launch configurations can only be launched from the Terminal view. \
+ Please open the Terminal view and click the view's Settings button to select and launch a local \
+ Terminal.
+errorLaunchConfigurationNoLongerExists=The launch configuration ''{0}'' that is selected in the \
+ Terminal Settings does no longer exist. Please open the Settings dialog to select a valid launch \
+ configuration.
+errorTitleCouldNotConnectToTerminal=Could not connect to Terminal
 warningTitleTerminalsStillRunning=Warning: Terminals with active processes are still running
 warningMessageTerminalsStillRunning=The workbench is about to be shut down even though one or more \
  terminals with active processes are still running. You may abort the shut-down of the workbench \

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalSettingsPage.java

@@ -37,6 +37,7 @@ import org.eclipse.swt.widgets.Layout;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Table;
 import org.eclipse.swt.widgets.Widget;
+import org.eclipse.tm.internal.terminal.local.launch.LocalTerminalLaunchUtilities;
 import org.eclipse.tm.internal.terminal.local.ui.DependentHeightComposite;
 import org.eclipse.tm.internal.terminal.provisional.api.ISettingsPage;
 import org.eclipse.tm.internal.terminal.provisional.api.Logger;
@@ -46,7 +47,7 @@ import org.eclipse.tm.internal.terminal.provisional.api.Logger;
  * local program connections.
  *
  * @author Mirko Raner
- * @version $Revision: 1.4 $
+ * @version $Revision: 1.1 $
  */
 public class LocalTerminalSettingsPage
 implements ISettingsPage, ISelectionChangedListener, SelectionListener {
@@ -78,6 +79,8 @@ implements ISettingsPage, ISelectionChangedListener, SelectionListener {
 	 */
 	public void createControl(Composite parent) {
 
+		ILaunchConfiguration defaultConfiguration;
+		defaultConfiguration = LocalTerminalLaunchUtilities.createDefaultLaunchConfiguration();
 		Composite enclosing = parent.getParent();
 		Layout enclosingLayout = enclosing.getLayout();
 		int extra = 0;
@@ -127,6 +130,13 @@ implements ISettingsPage, ISelectionChangedListener, SelectionListener {
 		//       in having it be a part of the ISettingsPage interface
 		//
 		loadSettings();
+		if (defaultConfiguration != null) {
+
+			// If there is only one configuration (the default one), then make sure it gets
+			// selected:
+			//
+			viewer.setSelection(new StructuredSelection(defaultConfiguration), true);
+		}
 	}
 
 	/**
@@ -229,8 +239,8 @@ implements ISettingsPage, ISelectionChangedListener, SelectionListener {
 			ILaunchConfigurationWorkingCopy newlyCreatedConfiguration;
 			ILaunchManager launchManager = DebugPlugin.getDefault().getLaunchManager();
 			String baseName = LocalTerminalMessages.newTerminalLaunchName;
-			String uniqueName = launchManager.generateUniqueLaunchConfigurationNameFrom(baseName);
+			String uniqueName = launchManager.generateLaunchConfigurationName(baseName);
-			ILaunchConfigurationType type = LocalTerminalUtilities.PROGRAM_LAUNCH_TYPE;
+			ILaunchConfigurationType type = LocalTerminalUtilities.TERMINAL_LAUNCH_TYPE;
 			try {
 
 				newlyCreatedConfiguration = type.newInstance(null, uniqueName);

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/LocalTerminalUtilities.java

@@ -28,7 +28,7 @@ import org.eclipse.tm.internal.terminal.provisional.api.Logger;
  * methods.
  *
  * @author Mirko Raner
- * @version $Revision: 1.3 $
+ * @version $Revision: 1.1 $
  */
 public class LocalTerminalUtilities {
 
@@ -56,10 +56,10 @@ public class LocalTerminalUtilities {
 	public final static ILaunchManager LAUNCH_MANAGER = DebugPlugin.getDefault().getLaunchManager();
 
 	/**
-	 * The {@link ILaunchConfigurationType} for "Program" launches (in the "External Tools"
+	 * The {@link ILaunchConfigurationType} for "Terminal" launches (in the "External Tools"
 	 * category).
 	 */
-	public final static ILaunchConfigurationType PROGRAM_LAUNCH_TYPE =
+	public final static ILaunchConfigurationType TERMINAL_LAUNCH_TYPE =
 		LAUNCH_MANAGER.getLaunchConfigurationType(LOCAL_TERMINAL);
 
 	/**
@@ -74,7 +74,7 @@ public class LocalTerminalUtilities {
 
 		ILaunchConfiguration[] configuration;
 		ILaunchManager manager = DebugPlugin.getDefault().getLaunchManager();
-		configuration = manager.getLaunchConfigurations(LocalTerminalUtilities.PROGRAM_LAUNCH_TYPE);
+		configuration = manager.getLaunchConfigurations(LocalTerminalUtilities.TERMINAL_LAUNCH_TYPE);
 		int numberOfConfigurations = configuration.length;
 		for (int index = 0; index < numberOfConfigurations; index++) {
 

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/launch/LocalTerminalLaunchDelegate.java

@@ -32,6 +32,7 @@ import org.eclipse.osgi.util.NLS;
 import org.eclipse.tm.internal.terminal.local.LocalTerminalActivator;
 import org.eclipse.tm.internal.terminal.local.LocalTerminalMessages;
 import org.eclipse.tm.internal.terminal.local.LocalTerminalUtilities;
+import org.eclipse.tm.internal.terminal.local.process.LocalTerminalProcessFactory;
 import org.eclipse.tm.internal.terminal.provisional.api.Logger;
 import org.eclipse.ui.PlatformUI;
 
@@ -43,7 +44,7 @@ import org.eclipse.ui.PlatformUI;
  * {@link ProcessFactory}, which allows the process to run with a pseudo-terminal ({@link PTY}).
  *
  * @author Mirko Raner and others
- * @version $Revision: 1.1 $
+ * @version $Revision: 1.2 $
  */
 public class LocalTerminalLaunchDelegate extends LaunchConfigurationDelegate {
 
@@ -80,6 +81,20 @@ public class LocalTerminalLaunchDelegate extends LaunchConfigurationDelegate {
 	public void launch(ILaunchConfiguration configuration, String mode, ILaunch launch,
 	IProgressMonitor progressMonitor) throws CoreException {
 
+		String processFactoryID;
+		processFactoryID = configuration.getAttribute(DebugPlugin.ATTR_PROCESS_FACTORY_ID, EMPTY);
+		if (!LocalTerminalProcessFactory.ID.equals(processFactoryID)) {
+
+			// This launch was not launched via the terminal connector UI but via the launch dialog;
+			// the launch needs to be explicitly connected to a terminal (otherwise it will appear
+			// in the regular console), so launching from the launch dialog or from the launch
+			// history is not supported right now.
+			//
+			String message = LocalTerminalMessages.errorDirectLaunch;
+			IStatus status = new Status(IStatus.ERROR, LocalTerminalActivator.PLUGIN_ID, message);
+			throw new CoreException(status);
+		}
+
 		// Extract all relevant information from the ILaunchConfiguration; the original
 		// ProgramLaunchDelegate class checks for cancellation again and again after each step,
 		// which is a somewhat suspect pattern; however, for now, LocalTerminalLaunchDelegate

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/launch/LocalTerminalLaunchUtilities.java

@@ -16,16 +16,20 @@ import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Path;
+import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.variables.IStringVariableManager;
 import org.eclipse.core.variables.VariablesPlugin;
 import org.eclipse.debug.core.DebugPlugin;
 import org.eclipse.debug.core.ILaunchConfiguration;
+import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
+import org.eclipse.debug.core.ILaunchManager;
 import org.eclipse.debug.ui.DebugUITools;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.tm.internal.terminal.local.LocalTerminalActivator;
 import org.eclipse.tm.internal.terminal.local.LocalTerminalMessages;
+import org.eclipse.tm.internal.terminal.local.LocalTerminalUtilities;
 import org.eclipse.tm.internal.terminal.provisional.api.Logger;
 
 /**
@@ -35,7 +39,7 @@ import org.eclipse.tm.internal.terminal.provisional.api.Logger;
  * because the original class is not part of the public API of its plug-in.
  *
  * @author Mirko Raner and others
- * @version $Revision: 1.2 $
+ * @version $Revision: 1.1 $
  */
 public class LocalTerminalLaunchUtilities {
 
@@ -176,6 +180,84 @@ public class LocalTerminalLaunchUtilities {
 		return null;
 	}
 
+	/**
+	 * Creates an initial default launch configuration for starting a shell if no terminal/program
+	 * launch configurations are defined yet.
+	 *
+	 * @return new {@link ILaunchConfiguration}, or {@code null} if there were already some
+	 * terminal/program launch configurations defined
+	 */
+	public static ILaunchConfiguration createDefaultLaunchConfiguration() {
+
+		ILaunchConfiguration[] configs;
+		ILaunchManager manager = LocalTerminalUtilities.LAUNCH_MANAGER;
+		try {
+
+			configs = manager.getLaunchConfigurations(LocalTerminalUtilities.TERMINAL_LAUNCH_TYPE);
+			if (configs == null || configs.length == 0) {
+
+				// Create a default launch configuration only if there aren't any terminal launch
+				// configurations defined at all:
+				//
+				ILaunchConfigurationWorkingCopy workingCopy;
+				workingCopy = createNewLaunchConfigurationWorkingCopy();
+				return workingCopy.doSave();
+			}
+		}
+		catch (CoreException exception)
+		{
+			exception.printStackTrace(); // TODO: implement proper exception handling
+		}
+		return null;
+	}
+
+	/**
+	 * Creates an {@link ILaunchConfigurationWorkingCopy} that uses the default shell as its
+	 * executable and the user's home directory as the working directory.
+	 *
+	 * @return an unsaved {@link ILaunchConfigurationWorkingCopy}
+	 * @throws CoreException if the {@link ILaunchConfigurationWorkingCopy} could not be
+	 * instantiated
+	 * @see #getDefaultShell()
+	 */
+	public static ILaunchConfigurationWorkingCopy createNewLaunchConfigurationWorkingCopy()
+	throws CoreException {
+
+		ILaunchConfigurationWorkingCopy workingCopy;
+		ILaunchManager manager = LocalTerminalUtilities.LAUNCH_MANAGER;
+		String userHome = System.getProperty("user.home", "/"); //$NON-NLS-1$//$NON-NLS-2$
+		String name = manager.generateLaunchConfigurationName("Terminal"); //$NON-NLS-1$
+		workingCopy = LocalTerminalUtilities.TERMINAL_LAUNCH_TYPE.newInstance(null, name);
+		workingCopy.setAttribute(ATTR_LOCATION, getDefaultShell().getAbsolutePath());
+		workingCopy.setAttribute(ATTR_WORKING_DIRECTORY, userHome);
+		return workingCopy;
+	}
+
+	/**
+	 * Returns the system's default shell. First, this method will read the value of the environment
+	 * variable {@code SHELL}. If that variable is not set, it will default to {@code cmd.exe} on
+	 * Windows systems, and to {@code /bin/sh} on all other systems.
+	 *
+	 * @return a {@link File} pointing to the default shell (the underlying file is not guaranteed
+	 * to exist in the file system)
+	 */
+	public static File getDefaultShell() {
+
+		String shell = System.getenv("SHELL"); //$NON-NLS-1$
+		if (shell == null) {
+
+			if (Platform.OS_WIN32.equals(Platform.getOS())) {
+
+				shell = "C:\\Windows\\System32\\cmd.exe"; //$NON-NLS-1$
+			}
+			else {
+
+				shell = "/bin/sh"; //$NON-NLS-1$
+			}
+		}
+		return new File(shell);
+	}
+
 	//------------------------------------- PRIVATE SECTION --------------------------------------//
 
 	private static IStringVariableManager getStringVariableManager() {

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/launch/ui/LocalTerminalLaunchTabGroup.java

@@ -34,12 +34,10 @@ import org.eclipse.tm.internal.terminal.provisional.api.Logger;
 * @author Mirko Raner
 * @version $Revision: 1.1 $
 **/
-public class LocalTerminalLaunchTabGroup extends AbstractLaunchConfigurationTabGroup
+public class LocalTerminalLaunchTabGroup extends AbstractLaunchConfigurationTabGroup {
-implements IDebugUIConstants {
 
 	private final static String ID = "id"; //$NON-NLS-1$
 	private final static String CLASS = "class"; //$NON-NLS-1$
-	private final static String LC_TAB_GROUPS = EXTENSION_POINT_LAUNCH_CONFIGURATION_TAB_GROUPS;
 	private final static String PROGRAM_TAB_GROUP =
 		"org.eclipse.ui.externaltools.launchConfigurationTabGroup.program"; //$NON-NLS-1$
 
@@ -81,7 +79,8 @@ implements IDebugUIConstants {
 		//
 		IConfigurationElement[] element;
 		IExtensionRegistry registry = Platform.getExtensionRegistry();
-		element = registry.getConfigurationElementsFor(IDebugUIConstants.PLUGIN_ID, LC_TAB_GROUPS);
+		final String TAB_GROUPS = IDebugUIConstants.EXTENSION_POINT_LAUNCH_CONFIGURATION_TAB_GROUPS;
+		element = registry.getConfigurationElementsFor(IDebugUIConstants.PLUGIN_ID, TAB_GROUPS);
 		int numberOfElements = element.length;
 		for (int index = 0; index < numberOfElements; index++) {
 

terminal/org.eclipse.tm.terminal.local/src/org/eclipse/tm/internal/terminal/local/launch/ui/LocalTerminalSettingsTab.java

@@ -38,7 +38,7 @@ import org.eclipse.tm.internal.terminal.provisional.api.Logger;
  * and the line separator string.
  *
  * @author Mirko Raner
- * @version $Revision: 1.2 $
+ * @version $Revision: 1.1 $
  **/
 public class LocalTerminalSettingsTab extends AbstractLaunchConfigurationTab
 implements SelectionListener {
@@ -230,6 +230,23 @@ implements SelectionListener {
 		configuration.setAttribute(LocalTerminalLaunchUtilities.ATTR_LINE_SEPARATOR, NULL);
 	}
 
+	/**
+	 * Prevents Terminal launch configurations from being started directly from the launch
+	 * configuration dialog. The <b>Run</b> button in the dialog will only be enabled if all tabs
+	 * consider a launch configuration valid.
+	 *
+	 * TODO: previously used launches can still be launched via the launch history
+	 *       (see {@code ExternalToolMenuDelegate#fillMenu(Menu)})
+	 *
+	 * @param configuration the {@link ILaunchConfiguration}
+	 * @return always {@code false}
+	 * @see org.eclipse.debug.ui.ILaunchConfigurationTab#isValid(ILaunchConfiguration)
+	 */
+	public boolean isValid(ILaunchConfiguration configuration) {
+
+		return false;
+	}
+
 	/**
 	 * Handles selection of any of the buttons in the tab.
 	 *