content: package mars.venus;
  
  import java.awt.event.ActionEvent;
  
  import javax.swing.Action;
  import javax.swing.Icon;
  import javax.swing.JOptionPane;
  import javax.swing.KeyStroke;
  
  import mars.Globals;
  import mars.mips.hardware.Coprocessor0;
  import mars.mips.hardware.Coprocessor1;
  import mars.mips.hardware.Memory;
  import mars.mips.hardware.RegisterFile;
  
  /*
   * Copyright (c) 2003-2009, Pete Sanderson and Kenneth Vollmar
   *
   * Developed by Pete Sanderson (psanderson@otterbein.edu) and Kenneth Vollmar
   * (kenvollmar@missouristate.edu)
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   *
   * (MIT license, http://www.opensource.org/licenses/mit-license.html)
   */
  
  /**
   * Action for the Run -> Backstep menu item
   */
  public class RunBackstepAction extends GuiAction {
  
  	/**
  	 *
  	 */
  	private static final long serialVersionUID = 4814940944425610191L;
  	String name;
  	ExecutePane executePane;
  
  	public RunBackstepAction(final String name, final Icon icon, final String descrip, final Integer mnemonic,
  			final KeyStroke accel, final VenusUI gui) {
  		super(name, icon, descrip, mnemonic, accel, gui);
  	}
  
  	/**
  	 * perform next simulated instruction step.
  	 */
  	@Override
  	public void actionPerformed(final ActionEvent e) {
  		name = getValue(Action.NAME).toString();
  		executePane = mainUI.getMainPane().getExecutePane();
  		if (!FileStatus.isAssembled()) {
  			// note: this should never occur since backstepping is only enabled after successful assembly.
  			JOptionPane.showMessageDialog(mainUI, "The program must be assembled before it can be run.");
  			return;
  		}
  		VenusUI.setStarted(true);
  		mainUI.messagesPane.setSelectedComponent(mainUI.messagesPane.runTab);
  		executePane.getTextSegmentWindow().setCodeHighlighting(true);
  
  		if (Globals.getSettings().getBackSteppingEnabled()) {
  			final boolean inDelaySlot = Globals.program.getBackStepper().inDelaySlot(); // Added 25 June 2007
  			Memory.getInstance().addObserver(executePane.getDataSegmentWindow());
  			RegisterFile.addRegistersObserver(executePane.getRegistersWindow());
  			Coprocessor0.addRegistersObserver(executePane.getCoprocessor0Window());
  			Coprocessor1.addRegistersObserver(executePane.getCoprocessor1Window());
  			Globals.program.getBackStepper().backStep();
  			Memory.getInstance().deleteObserver(executePane.getDataSegmentWindow());
  			RegisterFile.deleteRegistersObserver(executePane.getRegistersWindow());
  			executePane.getRegistersWindow().updateRegisters();
  			executePane.getCoprocessor1Window().updateRegisters();
  			executePane.getCoprocessor0Window().updateRegisters();
  			executePane.getDataSegmentWindow().updateValues();
  			executePane.getTextSegmentWindow().highlightStepAtPC(inDelaySlot); // Argument aded 25 June 2007
  			FileStatus.set(FileStatus.RUNNABLE);
  			// if we've backed all the way, disable the button
  			//    if (Globals.program.getBackStepper().empty()) {
  			//     ((AbstractAction)((AbstractButton)e.getSource()).getAction()).setEnabled(false);
  			//}
  			/*
  			if (pe !=null) {
  			RunGoAction.resetMaxSteps();
  			mainUI.getMessagesPane().postMarsMessage(
  			                    pe.errors().generateErrorReport());
  			mainUI.getMessagesPane().postMarsMessage(
  			                    "\n"+name+": execution terminated with errors.\n\n");
  			mainUI.getRegistersPane().setSelectedComponent(executePane.getCoprocessor0Window());
  			FileStatus.set(FileStatus.TERMINATED); // should be redundant.
  								executePane.getTextSegmentWindow().setCodeHighlighting(true);
  				executePane.getTextSegmentWindow().unhighlightAllSteps();
  			executePane.getTextSegmentWindow().highlightStepAtAddress(RegisterFile.getProgramCounter()-4);
  			}
  			*/
  			VenusUI.setReset(false);
  		}
  	}
  }
  