From 4ec8be746226144657027b4b13c8bee6d23b009d Mon Sep 17 00:00:00 2001
From: Aleksey Pivovarov <AMPivovarov@gmail.com>
Date: Tue, 20 Jul 2021 14:12:10 +0300
Subject: [PATCH] IDEA-274070 diff: support "Select Opposite Diff Pane" action
 for three-side viewers

GitOrigin-RevId: d4892afa4ad33fd257b01a9c0442a99ea5eb10b6
---
 .../util/side/ThreesideTextDiffViewer.java    | 31 ++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/platform/diff-impl/src/com/intellij/diff/tools/util/side/ThreesideTextDiffViewer.java b/platform/diff-impl/src/com/intellij/diff/tools/util/side/ThreesideTextDiffViewer.java
index 73962effdc83..116ad9136573 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/util/side/ThreesideTextDiffViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/util/side/ThreesideTextDiffViewer.java
@@ -16,6 +16,7 @@
 package com.intellij.diff.tools.util.side;
 
 import com.intellij.diff.DiffContext;
+import com.intellij.diff.actions.impl.FocusOppositePaneAction;
 import com.intellij.diff.actions.impl.OpenInEditorWithMouseAction;
 import com.intellij.diff.actions.impl.SetEditorSettingsAction;
 import com.intellij.diff.contents.DocumentContent;
@@ -33,8 +34,10 @@ import com.intellij.diff.tools.util.base.TextDiffViewerUtil;
 import com.intellij.diff.tools.util.breadcrumbs.SimpleDiffBreadcrumbsPanel;
 import com.intellij.diff.util.*;
 import com.intellij.openapi.actionSystem.AnAction;
+import com.intellij.openapi.actionSystem.AnActionEvent;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.editor.LogicalPosition;
+import com.intellij.openapi.editor.ScrollType;
 import com.intellij.openapi.editor.event.DocumentEvent;
 import com.intellij.openapi.editor.event.VisibleAreaEvent;
 import com.intellij.openapi.editor.event.VisibleAreaListener;
@@ -62,7 +65,8 @@ public abstract class ThreesideTextDiffViewer extends ThreesideDiffViewer<TextEd
   public ThreesideTextDiffViewer(@NotNull DiffContext context, @NotNull ContentDiffRequest request) {
     super(context, request, TextEditorHolder.TextEditorHolderFactory.INSTANCE);
 
-    //new MyFocusOppositePaneAction().setupAction(myPanel, this); // TODO
+    new MyFocusOppositePaneAction(true).install(myPanel);
+    new MyFocusOppositePaneAction(false).install(myPanel);
 
     myEditorSettingsAction = new SetEditorSettingsAction(getTextSettings(), getEditors());
     myEditorSettingsAction.applyDefaults();
@@ -391,4 +395,29 @@ public abstract class ThreesideTextDiffViewer extends ThreesideDiffViewer<TextEd
       return request;
     }
   }
+
+  private class MyFocusOppositePaneAction extends FocusOppositePaneAction {
+    MyFocusOppositePaneAction(boolean scrollToPosition) {
+      super(scrollToPosition);
+    }
+
+    @Override
+    public void actionPerformed(@NotNull AnActionEvent e) {
+      ThreeSide currentSide = getCurrentSide();
+      ThreeSide targetSide = currentSide.select(ThreeSide.BASE, ThreeSide.RIGHT, ThreeSide.LEFT); // cycle right
+
+      EditorEx targetEditor = getEditor(targetSide);
+
+      if (myScrollToPosition) {
+        LogicalPosition currentPosition = DiffUtil.getCaretPosition(getCurrentEditor());
+        LogicalPosition position = transferPosition(currentSide, targetSide, currentPosition);
+        targetEditor.getCaretModel().moveToLogicalPosition(position);
+      }
+
+      setCurrentSide(targetSide);
+      targetEditor.getScrollingModel().scrollToCaret(ScrollType.MAKE_VISIBLE);
+
+      DiffUtil.requestFocus(getProject(), getPreferredFocusedComponent());
+    }
+  }
 }