Reduce interaction with JCEF scrolling in the editor (#1226)

asciidoctor · Nov 25, 2022 · a44af5f · a44af5f
1 parent 8bfd335
commit a44af5f
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Showing 5 changed files with 25 additions and 6 deletions.
diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
@@ -10,6 +10,7 @@ This document provides a high-level view of the changes introduced by release.
 === 0.37.57
 
 - Fixing already disposed preview if devtools have been closed before
+- Reduce interaction with JCEF scrolling in the editor (#1226)
 
 === 0.37.56
 

diff --git a/src/main/java/org/asciidoc/intellij/editor/AsciiDocPreviewEditor.java b/src/main/java/org/asciidoc/intellij/editor/AsciiDocPreviewEditor.java
@@ -394,7 +394,6 @@ private void setupPanel() {
                 final AsciiDocApplicationSettings settings = AsciiDocApplicationSettings.getInstance();
                 myPanel = detachOldPanelAndCreateAndAttachNewOne(document, tempImagesPath, myHtmlPanelWrapper, null, retrievePanelProvider(settings));
                 myPanel.setEditor(editor);
-                myPanel.scrollToLine(targetLineNo, document.getLineCount());
                 forceRenderCycle();
                 renderIfVisible();
               }
@@ -650,7 +649,20 @@ public void dispose() {
 
   void scrollToLine(int line) {
     targetLineNo = line;
-    renderIfVisible();
+    boolean executed = false;
+    synchronized (lazyExecutor) {
+      if (lazyExecutor.isIdle()) {
+        lazyExecutor.execute(() -> {
+          if (myPanel != null) {
+            myPanel.scrollToLine(line, document.getLineCount());
+          }
+        });
+        executed = true;
+      }
+    }
+    if (!executed) {
+      renderIfVisible();
+    }
   }
 
   private class MyUpdatePanelOnSettingsChangedListener implements AsciiDocApplicationSettings.SettingsChangedListener {
@@ -673,7 +685,6 @@ public void onSettingsChange(@NotNull AsciiDocApplicationSettings settings) {
               if (!mySwingAlarm.isDisposed()) {
                 synchronized (this) {
                   myPanel = detachOldPanelAndCreateAndAttachNewOne(document, tempImagesPath, myHtmlPanelWrapper, myPanel, newPanelProvider);
-                  myPanel.scrollToLine(targetLineNo, document.getLineCount());
                   forceRenderCycle(); // force a refresh of the preview by resetting the current memorized content
                 }
                 renderIfVisible();

diff --git a/src/main/java/org/asciidoc/intellij/editor/LazyApplicationPoolExecutor.java b/src/main/java/org/asciidoc/intellij/editor/LazyApplicationPoolExecutor.java
@@ -70,11 +70,15 @@ public synchronized void execute(@NotNull final Runnable command) {
         }
       }
     };
-    if (myPooledAlarm.getActiveRequestCount() == 0 && (future == null || future.isDone())) {
+    if (isIdle()) {
       scheduleNext();
     }
   }
 
+  public boolean isIdle() {
+    return myPooledAlarm.getActiveRequestCount() == 0 && (future == null || future.isDone());
+  }
+
   private synchronized void scheduleNext() {
     final Runnable toSchedule = next;
     next = null;

diff --git a/src/main/java/org/asciidoc/intellij/editor/jcef/AsciiDocJCEFHtmlPanel.java b/src/main/java/org/asciidoc/intellij/editor/jcef/AsciiDocJCEFHtmlPanel.java
@@ -903,7 +903,10 @@ private boolean isDarcula() {
 
 
   @Override
-  public void scrollToLine(int line, int lineCount) {
+  public synchronized void scrollToLine(int line, int lineCount) {
+    if (this.lineCount == lineCount && this.line == line) {
+      return;
+    }
     this.lineCount = lineCount;
     this.line = line;
     try {

diff --git a/src/main/resources/org/asciidoc/intellij/editor/javafx/scrollToElement.js b/src/main/resources/org/asciidoc/intellij/editor/javafx/scrollToElement.js
@@ -91,7 +91,7 @@ window.__IntelliJTools.scrollToLine = (function () {
           (resultY < document.documentElement.scrollTop) || // position above window
           (resultY > document.documentElement.scrollTop + window.height) // position below window
          ) {
-        document.documentElement.scrollTop = document.body.scrollTop = newValue;
+        window.scrollTo({ top: newValue, left: 0, behavior: "auto" });
       }
 
       oldLineToScroll = newLineToScroll;