src/com/google/devrel/cluestick/studioclient/SearchResultsView.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.devrel.cluestick.studioclient;

import com.google.devrel.cluestick.searchservice.CluestickSearch;
import com.google.devrel.cluestick.searchservice.EventLog;

import com.appspot.cluestick_server.search.model.Result;
import com.intellij.CommonBundle;
import com.intellij.icons.AllIcons;
import com.intellij.ide.IdeBundle;
import com.intellij.openapi.Disposable;
import com.intellij.openapi.actionSystem.ActionManager;
import com.intellij.openapi.actionSystem.ActionPlaces;
import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;
import com.intellij.openapi.actionSystem.DefaultActionGroup;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.DumbAware;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.ui.Splitter;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.ui.DoubleClickListener;
import com.intellij.ui.OnePixelSplitter;
import com.intellij.ui.PopupHandler;
import com.intellij.ui.ScrollPaneFactory;
import com.intellij.ui.SmartExpander;
import com.intellij.util.ui.tree.TreeUtil;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.awt.BorderLayout;
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.List;

import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;

/**
 * SearchResultsView extends JPanel to show the entire Cluestick sample widget.
 */
public class SearchResultsView extends JPanel implements Disposable {

  private static final Logger LOG = Logger
      .getInstance("#com.google.devrel.cluestick.studioclient.SearchResultsView");

  private final EventLog eventLog;
  private final Splitter splitter;
  private final SearchResultsTree tree;
  private final Browser browser;
  private final JComponent secondComponent;
  private Runnable closeAction;

  public SearchResultsView(@NotNull final Project project, @NotNull final Symbol symbol,
      @NotNull final List<Result> results) {
    eventLog = new EventLog(ApplicationManager.getApplication().getService(CluestickSearch.class));

    setLayout(new BorderLayout());

    tree = new SearchResultsTree(symbol, results);
    tree.getSelectionModel().addTreeSelectionListener(new TreeSelectionListener() {
      @Override
      public void valueChanged(TreeSelectionEvent e) {
        syncBrowser();
      }
    });
    SmartExpander.installOn(tree);
    browser = new CodeBrowser(project, eventLog);

    splitter = new OnePixelSplitter(false, 0.5f);
    splitter.setFirstComponent(ScrollPaneFactory.createScrollPane(tree));

    secondComponent = ScrollPaneFactory.createScrollPane(browser.getPanel());
    splitter.setSecondComponent(secondComponent);
    secondComponent.setVisible(false);  // initially hide browser

    add(splitter, BorderLayout.CENTER);

    createActionsPanel();

    // Add action listeners. These listeners don't do anything if the target node isn't a leaf,
    // because trunk nodes respond by opening/closing on these same events. Users should use the
    // popup menu to open any relevant URLs instead.

    new DoubleClickListener() {
      @Override
      protected boolean onDoubleClick(MouseEvent event) {
        TreeNode node = getSingleSelectedNode();
        TreePath path = tree.getClosestPathForLocation(event.getX(), event.getY());
        if (node != null && node.isLeaf() && path != null && tree.isPathSelected(path)) {
          invokeSelectAction(node);
          return true;
        }
        return false;
      }
    }.installOn(tree);

    tree.addKeyListener(new KeyAdapter() {
      @Override
      public void keyPressed(KeyEvent e) {
        TreeNode node = getSingleSelectedNode();
        if (node != null && node.isLeaf() && e.getKeyCode() == KeyEvent.VK_ENTER) {
          invokeSelectAction(node);
        }
      }
    });

    DefaultActionGroup actionGroup = new DefaultActionGroup();
    actionGroup.add(new OpenURLAction());
    PopupHandler.installPopupMenu(tree, actionGroup, ActionPlaces.USAGE_VIEW_POPUP);

    TreeUtil.expandAll(tree);
  }

  /**
   * @param close The code to run when the Close button is pressed.
   */
  public void setClose(Runnable close) {
    this.closeAction = close;
  }

  private void invokeSelectAction(@Nullable TreeNode node) {
    String url = getURLForNode(node);
    if (url != null) {
      openExternalBrowser(url);
    }
  }

  @Nullable private String getURLForNode(@Nullable TreeNode node) {
    if (node instanceof SearchResultsNode) {
      String url = ((SearchResultsNode) node).getURL();
      if (!StringUtil.isEmpty(url)) {
        return url;
      }
    }
    return null;
  }

  private void openExternalBrowser(@NotNull String url) {
    LOG.info(String.format("Opening URL: `%s`", url));

    // In nearly all cases, this will load the user's browser with the target URL. However,
    // swallow its exceptions for sanity.
    try {
      Desktop.getDesktop().browse(new URI(url));
    } catch (URISyntaxException ignored) {
      // Thrown if the URL is bad.
    } catch (IOException ignored) {
      // Thrown if a browser can't be found or run.
    } catch (RuntimeException ignored) {
      // Thrown on a variety of other reasons, see-
      // http://docs.oracle.com/javase/7/docs/api/java/awt/Desktop.html#browse(java.net.URI)
    }
  }

  /**
   * Create and add a JPanel containing default actions. This just includes Close for now.
   */
  private void createActionsPanel() {
    DefaultActionGroup group = new DefaultActionGroup();
    group.add(new CloseAction());

    ActionManager actionManager = ActionManager.getInstance();
    JComponent actionsToolbar = actionManager
        .createActionToolbar(ActionPlaces.CODE_INSPECTION, group, false).getComponent();

    JPanel actionsPanel = new JPanel(new BorderLayout());
    actionsPanel.add(actionsToolbar, BorderLayout.WEST);
    add(actionsPanel, BorderLayout.WEST);
  }

  @Override
  public void dispose() {
    splitter.dispose();
    eventLog.cancel();

    if (browser instanceof Disposable) {
      ((Disposable) browser).dispose();
    }
  }

  private TreeNode getSingleSelectedNode() {
    TreeSelectionModel selectionModel = tree.getSelectionModel();
    if (selectionModel.getSelectionCount() == 1) {
      TreePath pathSelected = tree.getSelectionModel().getLeadSelectionPath();
      if (pathSelected != null) {
        return (TreeNode) pathSelected.getLastPathComponent();
      }
    }
    return null;
  }

  private void syncBrowser() {
    boolean visible = false;
    TreeNode node = getSingleSelectedNode();
    if (node instanceof SearchResultsNode) {
      Result result = ((SearchResultsNode) node).getSearchResult();
      if (result != null && showInBrowser(result)) {
        visible = true;
      }
    }

    if (!visible) {
      browser.showEmpty();
    }
    if (secondComponent.isVisible() != visible) {
      secondComponent.setVisible(visible);
      splitter.doLayout();
      splitter.doLayout();  // run twice, in case skipNextLayouting() was called on Splitter
    }
  }

  /**
   * Shows the given {@link Result} inside the current {@link Browser}.
   * @param result The result to show.
   * @return Whether the result could be shown.
   */
  private boolean showInBrowser(@NotNull Result result) {
    // TODO(thorogood): Make this part of Browser interface.
    if (result.getCode() == null) {
      return false;
    }

    Cursor currentCursor = getCursor();
    setCursor(new Cursor(Cursor.WAIT_CURSOR));
    browser.showResult(result);
    setCursor(currentCursor);
    return true;
  }

  private class OpenURLAction extends AnAction {
    private OpenURLAction() {
      super(IdeBundle.message("open.url.in.browser.tooltip"), null, null);
    }

    @Override
    public void update(AnActionEvent e) {
      String url = getURLForNode(getSingleSelectedNode());
      e.getPresentation().setVisible(url != null);
    }

    @Override
    public void actionPerformed(AnActionEvent e) {
      invokeSelectAction(getSingleSelectedNode());
    }
  }

  private class CloseAction extends AnAction implements DumbAware {
    private CloseAction() {
      super(CommonBundle.message("action.close"), null, AllIcons.Actions.Cancel);
    }

    @Override
    public void actionPerformed(AnActionEvent e) {
      if (closeAction != null) {
        closeAction.run();
      }
    }
  }
}