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.ProcessingException;
  import mars.mips.hardware.RegisterFile;
  import mars.simulator.ProgramArgumentList;
  import mars.simulator.Simulator;
  
  /*
   * Copyright (c) 2003-2006, 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 -> Step menu item
   */
  public class RunStepAction extends GuiAction {
  
  	/**
  	 *
  	 */
  	private static final long serialVersionUID = 3825313078523126501L;
  	String name;
  	ExecutePane executePane;
  
  	public RunStepAction(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()) {
  			if (!VenusUI.getStarted()) {  // DPS 17-July-2008
  				processProgramArgumentsIfAny();
  			}
  			VenusUI.setStarted(true);
  			mainUI.messagesPane.setSelectedComponent(mainUI.messagesPane.runTab);
  			executePane.getTextSegmentWindow().setCodeHighlighting(true);
  			try {
  				Globals.program.simulateStepAtPC(this);
  			} catch (final ProcessingException ev) {}
  		} else {
  			// note: this should never occur since "Step" is only enabled after successful assembly.
  			JOptionPane.showMessageDialog(mainUI, "The program must be assembled before it can be run.");
  		}
  	}
  
  	// When step is completed, control returns here (from execution thread, indirectly)
  	// to update the GUI.
  	public void stepped(final boolean done, final int reason, final ProcessingException pe) {
  		executePane.getRegistersWindow().updateRegisters();
  		executePane.getCoprocessor1Window().updateRegisters();
  		executePane.getCoprocessor0Window().updateRegisters();
  		executePane.getDataSegmentWindow().updateValues();
  		if (!done) {
  			executePane.getTextSegmentWindow().highlightStepAtPC();
  			FileStatus.set(FileStatus.RUNNABLE);
  		}
  		if (done) {
  			RunGoAction.resetMaxSteps();
  			executePane.getTextSegmentWindow().unhighlightAllSteps();
  			FileStatus.set(FileStatus.TERMINATED);
  		}
  		if (done && pe == null) {
  			mainUI.getMessagesPane().postMarsMessage("\n" + name + ": execution "
  					+ (reason == Simulator.CLIFF_TERMINATION ? "terminated due to null instruction."
  							: "completed successfully.") + "\n\n");
  			mainUI.getMessagesPane().postRunMessage("\n-- program is finished running "
  					+ (reason == Simulator.CLIFF_TERMINATION ? "(dropped off bottom)" : "") + " --\n\n");
  			mainUI.getMessagesPane().selectRunMessageTab();
  		}
  		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);
  	}
  
  	////////////////////////////////////////////////////////////////////////////////////
  	// Method to store any program arguments into MIPS memory and registers before
  	// execution begins. Arguments go into the gap between $sp and kernel memory.
  	// Argument pointers and count go into runtime stack and $sp is adjusted accordingly.
  	// $a0 gets argument count (argc), $a1 gets stack address of first arg pointer (argv).
  	private void processProgramArgumentsIfAny() {
  		final String programArguments = executePane.getTextSegmentWindow().getProgramArguments();
  		if (programArguments == null || programArguments.length() == 0 || !Globals.getSettings()
  				.getProgramArguments()) {
  			return;
  		}
  		new ProgramArgumentList(programArguments).storeProgramArguments();
  	}
  }
  