com.google.eclipse.terminal.local/src/com/google/eclipse/terminal/local/ui/preferences/ColorsPreferencePage.java

/*
 * Copyright (c) 2012 Google Inc.
 *
 * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
 * Public License v1.0 which accompanies this distribution, and is available at
 *
 * http://www.eclipse.org/legal/epl-v10.html
 */
package com.google.eclipse.terminal.local.ui.preferences;

import static com.google.eclipse.terminal.local.Activator.log;
import static org.eclipse.jface.preference.ColorSelector.PROP_COLORCHANGE;
import static org.eclipse.swt.SWT.*;

import java.util.Scanner;

import org.eclipse.jface.preference.*;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.source.projection.ProjectionViewer;
import org.eclipse.jface.util.*;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.*;

/**
 * @author alruiz@google.com (Alex Ruiz)
 */
public class ColorsPreferencePage extends PreferencePage implements IWorkbenchPreferencePage {
  private ProjectionViewer previewer;
  private ColorSelector foregroundColorSelector;
  private ColorSelector backgroundColorSelector;

  public ColorsPreferencePage() {
  }

  @Override public void init(IWorkbench workbench) {
  }

  @Override protected Control createContents(Composite parent) {
    Composite contents = new Composite(parent, NONE);
    contents.setLayout(new GridLayout(1, false));
    Label lblDescription = new Label(contents, SWT.NONE);
    lblDescription.setText("Local terminal color preferences.");
    new Label(contents, SWT.NONE);
    Composite controls = new Composite(contents, SWT.NONE);
    controls.setLayout(new GridLayout(2, false));
    Label lblBackground = new Label(controls, SWT.NONE);
    lblBackground.setText("Background:");
    backgroundColorSelector = new ColorSelector(controls);
    Label lblForeground = new Label(controls, SWT.NONE);
    lblForeground.setText("Foreground:");
    foregroundColorSelector = new ColorSelector(controls);
    new Label(contents, SWT.NONE);
    Label lblPreview = new Label(contents, SWT.NONE);
    lblPreview.setText("Preview:");
    previewer = new ProjectionViewer(contents, null, null, false, V_SCROLL | H_SCROLL);
    previewer.setEditable(false);
    previewer.setDocument(new Document(loadContentsFrom("ColorSettingPreviewText.txt")));
    StyledText previewerText = previewer.getTextWidget();
    previewerText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
    Cursor arrowCursor = previewerText.getDisplay().getSystemCursor(CURSOR_ARROW);
    previewerText.setCursor(arrowCursor);
    Display display = getShell().getDisplay();
    backgroundColorSelector.addListener(new ColorChangeListener(display) {
      @Override void updateColor(Color color) {
        previewer.getTextWidget().setBackground(color);
      }
    });
    foregroundColorSelector.addListener(new ColorChangeListener(display) {
      @Override void updateColor(Color color) {
        previewer.setTextColor(color);
      }
    });
    return contents;
  }

  private String loadContentsFrom(String fileName) {
    String lineSeparator = System.getProperty("line.separator");
    StringBuilder buffer = new StringBuilder();
    Scanner scanner = null;
    try {
      scanner = new Scanner(getClass().getResourceAsStream(fileName));
      while (scanner.hasNextLine()) {
        String line = scanner.nextLine();
        buffer.append(line).append(lineSeparator);
      }
    } catch (RuntimeException e) {
      log("Unable to load preview content", e);
    } finally {
      if (scanner != null) {
        scanner.close();
      }
    }
    return buffer.toString();
  }

  private static abstract class ColorChangeListener implements IPropertyChangeListener {
    private final Device device;

    private ColorChangeListener(Device device) {
      this.device = device;
    }

    @Override public final void propertyChange(PropertyChangeEvent event) {
      if (PROP_COLORCHANGE.equals(event.getProperty())) {
        RGB rgb = (RGB) event.getNewValue();
        updateColor(new Color(device, rgb));
      }
    }

    abstract void updateColor(Color color);
  }
}