added simple preview for restructured text

python/python-rest/resources/META-INF/python-rest-plugin.xml

@@ -26,4 +26,8 @@
     </action>
 
   </actions>
+
+  <extensions defaultExtensionNs="restructured.text">
+    <html.preview.provider implementation="com.jetbrains.rest.RestPythonPreviewProvider" />
+  </extensions>
 </idea-plugin>

python/python-rest/src/com/jetbrains/rest/RestPythonPreviewProvider.java

@@ -0,0 +1,43 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.rest;
+
+import com.google.common.collect.Lists;
+import com.intellij.execution.configurations.GeneralCommandLine;
+import com.intellij.execution.process.ProcessOutput;
+import com.intellij.openapi.module.Module;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.projectRoots.Sdk;
+import com.intellij.openapi.roots.ProjectFileIndex;
+import com.intellij.openapi.vfs.CharsetToolkit;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.jetbrains.python.sdk.PySdkUtil;
+import com.jetbrains.python.sdk.PythonSdkType;
+import com.jetbrains.rest.editor.RestPreviewProvider;
+import org.jetbrains.annotations.Nullable;
+
+import static com.jetbrains.python.PythonHelper.REST_RUNNER;
+
+public class RestPythonPreviewProvider extends RestPreviewProvider {
+
+  @Nullable
+  public String toHtml(String text, VirtualFile virtualFile, Project project) {
+    Module module = ProjectFileIndex.SERVICE.getInstance(project).getModuleForFile(virtualFile);
+    if (module == null) return null;
+
+    final Sdk sdk = PythonSdkType.findPythonSdk(module);
+    if (sdk == null) {
+      return null;
+    }
+    final String sdkHomePath = sdk.getHomePath();
+    if (sdkHomePath == null) {
+      return null;
+    }
+
+    final GeneralCommandLine commandLine = REST_RUNNER.newCommandLine(sdkHomePath, Lists.newArrayList("rst2html"));
+    final ProcessOutput output = PySdkUtil.getProcessOutput(commandLine, virtualFile.getParent().getPath(), null, 5000,
+                                                            text.getBytes(CharsetToolkit.UTF8_CHARSET), true);
+    if (output.isCancelled() || output.isTimeout()) return null;
+
+    return output.getStdout();
+  }
+}

python/rest/intellij.reStructuredText.iml

@@ -15,5 +15,6 @@
     <orderEntry type="library" name="Guava" level="project" />
     <orderEntry type="module" module-name="intellij.spellchecker" />
     <orderEntry type="module" module-name="intellij.platform.testFramework" scope="TEST" />
+    <orderEntry type="library" name="com.googlecode.owasp-java-html-sanitizer:owasp-java-html-sanitizer:20180219.1" level="project" />
   </component>
 </module>

python/rest/resources/META-INF/rest.xml

@@ -1,4 +1,8 @@
 <idea-plugin>
+  <extensionPoints>
+    <extensionPoint qualifiedName="restructured.text.html.preview.provider" interface="com.jetbrains.rest.editor.RestPreviewProvider" />
+  </extensionPoints>
+
   <extensions defaultExtensionNs="com.intellij">
 
     <fileTypeFactory implementation="com.jetbrains.rest.RestFileTypeFactory"/>
@@ -25,6 +29,8 @@
 
     <indexPatternBuilder implementation="com.jetbrains.rest.RestIndexPatternBuilder" />
     <todoIndexer filetype="ReST" implementationClass="com.jetbrains.rest.RestTodoIndexer" />
+
+    <fileEditorProvider implementation="com.jetbrains.rest.editor.RestSplitEditorProvider"/>
   </extensions>
 
   <extensions defaultExtensionNs="com.intellij.spellchecker">

python/rest/src/com/jetbrains/rest/editor/RestPreviewFileEditor.java

@@ -0,0 +1,201 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.rest.editor;
+
+import com.intellij.codeHighlighting.BackgroundEditorHighlighter;
+import com.intellij.openapi.application.ModalityState;
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.event.DocumentEvent;
+import com.intellij.openapi.editor.event.DocumentListener;
+import com.intellij.openapi.fileEditor.FileDocumentManager;
+import com.intellij.openapi.fileEditor.FileEditor;
+import com.intellij.openapi.fileEditor.FileEditorLocation;
+import com.intellij.openapi.fileEditor.FileEditorState;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.util.NotNullLazyValue;
+import com.intellij.openapi.util.UserDataHolderBase;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.ui.javafx.JavaFxHtmlPanel;
+import com.intellij.util.Alarm;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.owasp.html.HtmlPolicyBuilder;
+import org.owasp.html.PolicyFactory;
+import org.owasp.html.Sanitizers;
+
+import javax.swing.*;
+import java.beans.PropertyChangeListener;
+
+public class RestPreviewFileEditor extends UserDataHolderBase implements FileEditor {
+  private final static long PARSING_CALL_TIMEOUT_MS = 50L;
+
+  private final static long RENDERING_DELAY_MS = 20L;
+
+  final static NotNullLazyValue<PolicyFactory> SANITIZER_VALUE = new NotNullLazyValue<PolicyFactory>() {
+    @NotNull
+    @Override
+    protected PolicyFactory compute() {
+      return Sanitizers.BLOCKS
+        .and(Sanitizers.FORMATTING)
+        .and(new HtmlPolicyBuilder()
+               .allowUrlProtocols("file", "http", "https").allowElements("img")
+               .allowAttributes("alt", "src", "title").onElements("img")
+               .allowAttributes("border", "height", "width").onElements("img")
+               .toFactory())
+        .and(new HtmlPolicyBuilder()
+               .allowUrlProtocols("file", "http", "https", "mailto").allowElements("a")
+               .allowAttributes("href", "title").onElements("a")
+               .toFactory())
+        .and(Sanitizers.TABLES)
+        .and(new HtmlPolicyBuilder()
+               .allowElements("code", "tr")
+               .allowAttributes("class").onElements("code", "tr")
+               .toFactory());
+    }
+  };
+  @NotNull
+  private final JavaFxHtmlPanel myPanel;
+  @NotNull
+  private final VirtualFile myFile;
+  private final Project myProject;
+  @Nullable
+  private final Document myDocument;
+  @NotNull
+  private final Alarm myPooledAlarm = new Alarm(Alarm.ThreadToUse.POOLED_THREAD, this);
+  @NotNull
+  private final Alarm mySwingAlarm = new Alarm(Alarm.ThreadToUse.SWING_THREAD, this);
+
+  private final Object REQUESTS_LOCK = new Object();
+  @Nullable
+  private Runnable myLastRequest = null;
+
+  @NotNull
+  private String myLastRenderedHtml = "";
+
+  public RestPreviewFileEditor(@NotNull VirtualFile file, Project project) {
+    myFile = file;
+    myProject = project;
+    myDocument = FileDocumentManager.getInstance().getDocument(myFile);
+    myPanel = new JavaFxHtmlPanel();
+
+    if (myDocument != null) {
+      myDocument.addDocumentListener(new DocumentListener() {
+
+        @Override
+        public void beforeDocumentChange(DocumentEvent e) {
+          myPooledAlarm.cancelAllRequests();
+        }
+
+        @Override
+        public void documentChanged(final DocumentEvent e) {
+          myPooledAlarm.addRequest(() -> updateHtml(), PARSING_CALL_TIMEOUT_MS);
+        }
+      }, this);
+    }
+  }
+
+  @NotNull
+  @Override
+  public JComponent getComponent() {
+    return myPanel.getComponent();
+  }
+
+  @Nullable
+  @Override
+  public JComponent getPreferredFocusedComponent() {
+    return myPanel.getComponent();
+  }
+
+  @NotNull
+  @Override
+  public String getName() {
+    return "ReStructuredText HTML Preview";
+  }
+
+  @Override
+  public void setState(@NotNull FileEditorState state) {
+  }
+
+  @Override
+  public boolean isModified() {
+    return false;
+  }
+
+  @Override
+  public boolean isValid() {
+    return true;
+  }
+
+  @Override
+  public void selectNotify() {
+    myPooledAlarm.cancelAllRequests();
+    myPooledAlarm.addRequest(() -> updateHtml(), 0);
+  }
+
+  /**
+   * Is always run from pooled thread
+   */
+  private void updateHtml() {
+    if (!myFile.isValid() || myDocument == null || Disposer.isDisposed(this)) {
+      return;
+    }
+
+    final String html = RestPreviewProvider.getProviders()[0].toHtml(myDocument.getText(), myFile, myProject);
+    if (html == null) {
+      return;
+    }
+
+    // EA-75860: The lines to the top may be processed slowly; Since we're in pooled thread, we can be disposed already.
+    if (!myFile.isValid() || Disposer.isDisposed(this)) {
+      return;
+    }
+
+    synchronized (REQUESTS_LOCK) {
+      if (myLastRequest != null) {
+        mySwingAlarm.cancelRequest(myLastRequest);
+      }
+      myLastRequest = () -> {
+        final String currentHtml = "<html>" + SANITIZER_VALUE.getValue().sanitize(html) + "</html>";
+        if (!currentHtml.equals(myLastRenderedHtml)) {
+          myLastRenderedHtml = currentHtml;
+          myPanel.setHtml(myLastRenderedHtml);
+        }
+
+        myPanel.render();
+        synchronized (REQUESTS_LOCK) {
+          myLastRequest = null;
+        }
+      };
+      mySwingAlarm.addRequest(myLastRequest, RENDERING_DELAY_MS, ModalityState.stateForComponent(getComponent()));
+    }
+  }
+
+  @Override
+  public void deselectNotify() {
+  }
+
+  @Override
+  public void addPropertyChangeListener(@NotNull PropertyChangeListener listener) {
+  }
+
+  @Override
+  public void removePropertyChangeListener(@NotNull PropertyChangeListener listener) {
+  }
+
+  @Nullable
+  @Override
+  public BackgroundEditorHighlighter getBackgroundHighlighter() {
+    return null;
+  }
+
+  @Nullable
+  @Override
+  public FileEditorLocation getCurrentLocation() {
+    return null;
+  }
+
+  @Override
+  public void dispose() {
+    Disposer.dispose(myPanel);
+  }
+}

python/rest/src/com/jetbrains/rest/editor/RestPreviewProvider.java

@@ -0,0 +1,22 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.rest.editor;
+
+import com.intellij.openapi.extensions.ExtensionPointName;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.VirtualFile;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public abstract class RestPreviewProvider {
+  public static final ExtensionPointName<RestPreviewProvider> EP_NAME =
+    ExtensionPointName.create("restructured.text.html.preview.provider");
+
+  @Nullable
+  public abstract String toHtml(String text, VirtualFile virtualFile, Project project);
+
+  @NotNull
+  public static RestPreviewProvider[] getProviders() {
+    return EP_NAME.getExtensions();
+  }
+
+}

python/rest/src/com/jetbrains/rest/editor/RestSplitEditorProvider.java

@@ -0,0 +1,39 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.rest.editor;
+
+import com.intellij.openapi.fileEditor.*;
+import com.intellij.openapi.fileEditor.impl.text.TextEditorProvider;
+import com.intellij.openapi.project.DumbAware;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.jetbrains.rest.RestFileType;
+import org.jetbrains.annotations.NotNull;
+
+public class RestSplitEditorProvider implements FileEditorProvider, DumbAware {
+  public RestSplitEditorProvider() {
+  }
+
+  @Override
+  public boolean accept(@NotNull Project project, @NotNull VirtualFile file) {
+    return file.getFileType() == RestFileType.INSTANCE;
+  }
+
+  @NotNull
+  @Override
+  public FileEditor createEditor(@NotNull Project project, @NotNull VirtualFile file) {
+    TextEditor editor = (TextEditor)TextEditorProvider.getInstance().createEditor(project, file);
+    return new TextEditorWithPreview(editor, new RestPreviewFileEditor(file, project));
+  }
+
+  @NotNull
+  @Override
+  public String getEditorTypeId() {
+    return "restructured-text-editor";
+  }
+
+  @NotNull
+  @Override
+  public FileEditorPolicy getPolicy() {
+    return FileEditorPolicy.HIDE_DEFAULT_EDITOR;
+  }
+}