[FIX][I] #711 Ignore non-text editors for editor state

Adjusts the logic sharing the local editor state to ignore the opening
of non-text editors.

Adjusts the logic sharing the local editor state to ignore the closing
of editors not known to the editor pool.

With this change, non-text editors are completely ignored by Saros/I.
This was done to match the Eclipse handling of such non-text editors.

Partial fix for #711.

intellij/src/saros/intellij/editor/LocalEditorHandler.java

@@ -2,6 +2,8 @@
 
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.fileEditor.FileEditor;
+import com.intellij.openapi.fileEditor.TextEditor;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vfs.VirtualFile;
 import org.apache.log4j.Logger;
@@ -153,15 +155,20 @@ private Editor openEditor(
   }
 
   /**
-   * Removes a file from the editorPool and calls {@link EditorManager#generateEditorClosed(SPath)}
+   * Removes a file from the editorPool and calls {@link EditorManager#generateEditorClosed(SPath)}.
+   *
+   * <p>Does nothing if the file is not shared or not known to the editor pool.
    *
    * @param project the project in which to close the editor
    * @param virtualFile the file for which to close the editor
    */
   public void closeEditor(@NotNull Project project, @NotNull VirtualFile virtualFile) {
     SPath path = VirtualFileConverter.convertToSPath(project, virtualFile);
 
-    if (path != null && sarosSession.isShared(path.getResource())) {
+    if (path != null
+        && sarosSession.isShared(path.getResource())
+        && editorPool.getEditor(path) != null) {
+
       editorPool.removeEditor(path);
       manager.generateEditorClosed(path);
     }
@@ -217,8 +224,9 @@ public void saveDocument(@NotNull SPath path) {
    * @param project the project in which to activate the editor
    * @param file the file whose editor was activated or <code>null</code> if there is no editor open
    */
-  public void activateEditor(@NotNull Project project, @Nullable VirtualFile file) {
-    if (file == null) {
+  public void activateEditor(
+      @NotNull Project project, @Nullable VirtualFile file, @Nullable FileEditor fileEditor) {
+    if (file == null || fileEditor == null) {
 
       if (manager.hasSession()) {
         manager.generateEditorActivated(null);
@@ -227,6 +235,12 @@ public void activateEditor(@NotNull Project project, @Nullable VirtualFile file)
       return;
     }
 
+    if (!(fileEditor instanceof TextEditor)) {
+      LOG.debug("Ignoring opened non-text editor for file " + file);
+
+      return;
+    }
+
     SPath path = VirtualFileConverter.convertToSPath(project, file);
 
     if (path != null && sarosSession.isShared(path.getResource())) {

intellij/src/saros/intellij/eventhandler/editor/editorstate/EditorStatusChangeActivityDispatcher.java

@@ -1,5 +1,6 @@
 package saros.intellij.eventhandler.editor.editorstate;
 
+import com.intellij.openapi.fileEditor.FileEditor;
 import com.intellij.openapi.fileEditor.FileEditorManager;
 import com.intellij.openapi.fileEditor.FileEditorManagerEvent;
 import com.intellij.openapi.fileEditor.FileEditorManagerListener;
@@ -53,13 +54,13 @@ private void generateEditorClosedActivity(@NotNull VirtualFile virtualFile) {
   }
 
   /**
-   * Calls {@link LocalEditorHandler#activateEditor(Project, VirtualFile)}.
+   * Calls {@link LocalEditorHandler#activateEditor(Project, VirtualFile, FileEditor)}.
    *
    * @param event the event to react to
    * @see FileEditorManagerListener#selectionChanged(FileEditorManagerEvent)
    */
   private void generateEditorActivatedActivity(@NotNull FileEditorManagerEvent event) {
-    localEditorHandler.activateEditor(project, event.getNewFile());
+    localEditorHandler.activateEditor(project, event.getNewFile(), event.getNewEditor());
   }
 
   @Override