diff: fix "Show All Files in One Diff View" not working for VCS Log preview

GitOrigin-RevId: 8639ee150dae3d7bb2f5cc1a6b7e42a47790499e

platform/diff-impl/api-dump-experimental.txt

@@ -100,6 +100,7 @@ f:com.intellij.diff.tools.combined.CombinedDiffKeysKt
 - a:goPrevDiff():V
 *f:com.intellij.diff.tools.combined.CombinedDiffRegistry
 - sf:INSTANCE:com.intellij.diff.tools.combined.CombinedDiffRegistry
+- f:addStateListener(java.lang.Runnable,com.intellij.openapi.Disposable):V
 - f:getFilesLimit():I
 - f:getMaxBlockCountInMemory():I
 - f:getPreloadedBlocksCount():I

platform/diff-impl/src/com/intellij/diff/tools/combined/CombinedDiffRegistry.kt

@@ -4,6 +4,8 @@ package com.intellij.diff.tools.combined
 import com.intellij.diff.editor.DiffEditorViewerFileEditor.Companion.reloadDiffEditorsForFiles
 import com.intellij.diff.editor.DiffViewerVirtualFile
 import com.intellij.idea.AppMode
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.options.advanced.AdvancedSettings
 import com.intellij.openapi.options.advanced.AdvancedSettingsChangeListener
 import com.intellij.openapi.project.ProjectManager
@@ -27,6 +29,17 @@ object CombinedDiffRegistry {
   fun getMaxBlockCountInMemory(): Int = Registry.intValue("combined.diff.loaded.content.limit")
 
   fun getFilesLimit(): Int = Registry.intValue("combined.diff.files.limit")
+
+  fun addStateListener(onEnabledChange: Runnable, disposable: Disposable) {
+    ApplicationManager.getApplication().messageBus.connect(disposable)
+      .subscribe(AdvancedSettingsChangeListener.TOPIC, object : AdvancedSettingsChangeListener {
+        override fun advancedSettingChanged(id: String, oldValue: Any, newValue: Any) {
+          if (id == COMBINED_DIFF_SETTING_ID) {
+            onEnabledChange.run()
+          }
+        }
+      })
+  }
 }
 
 internal class CombinedDiffAdvancedSettingsChangeListener : AdvancedSettingsChangeListener {

platform/vcs-log/impl/src/com/intellij/vcs/log/ui/frame/FrameDiffPreview.kt

@@ -2,6 +2,7 @@
 package com.intellij.vcs.log.ui.frame
 
 import com.intellij.diff.impl.DiffEditorViewer
+import com.intellij.diff.tools.combined.CombinedDiffRegistry
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.actionSystem.ActionToolbar
 import com.intellij.openapi.application.invokeLater
@@ -17,11 +18,13 @@ import org.jetbrains.annotations.NonNls
 import javax.swing.JComponent
 import kotlin.math.roundToInt
 
-internal abstract class FrameDiffPreview(uiProperties: VcsLogUiProperties,
-                                         mainComponent: JComponent,
-                                         @NonNls splitterProportionKey: String,
-                                         defaultProportion: Float = 0.7f,
-                                         parentDisposable: Disposable) : Disposable {
+internal abstract class FrameDiffPreview(
+  val uiProperties: VcsLogUiProperties,
+  mainComponent: JComponent,
+  @NonNls splitterProportionKey: String,
+  defaultProportion: Float = 0.7f,
+  parentDisposable: Disposable,
+) : Disposable {
   private val previewDiffSplitter: Splitter = OnePixelSplitter(uiProperties[MainVcsLogUiProperties.DIFF_PREVIEW_VERTICAL_SPLIT],
                                                                splitterProportionKey, defaultProportion)
 
@@ -35,14 +38,15 @@ internal abstract class FrameDiffPreview(uiProperties: VcsLogUiProperties,
 
     uiProperties.onPropertyChange(this) { p ->
       if (CommonUiProperties.SHOW_DIFF_PREVIEW == p) {
-        showDiffPreview(uiProperties[CommonUiProperties.SHOW_DIFF_PREVIEW])
+        updateDiffPreviewState()
       }
       else if (MainVcsLogUiProperties.DIFF_PREVIEW_VERTICAL_SPLIT == p) {
         changeDiffPreviewOrientation(uiProperties[MainVcsLogUiProperties.DIFF_PREVIEW_VERTICAL_SPLIT])
       }
     }
-    invokeLater { showDiffPreview(uiProperties[CommonUiProperties.SHOW_DIFF_PREVIEW]) }
+    CombinedDiffRegistry.addStateListener({ updateDiffPreviewState(forceRecreate = true) }, this)
 
+    invokeLater { updateDiffPreviewState() }
     Disposer.register(parentDisposable, this)
   }
 
@@ -59,13 +63,20 @@ internal abstract class FrameDiffPreview(uiProperties: VcsLogUiProperties,
     return diffViewer?.preferredFocusedComponent
   }
 
-  private fun showDiffPreview(state: Boolean) {
+  private fun updateDiffPreviewState(forceRecreate: Boolean = false) {
     if (isDisposed) return
+    val shouldBeShown = uiProperties[CommonUiProperties.SHOW_DIFF_PREVIEW]
 
     val isShown = diffViewer != null
-    if (state == isShown) return
+    if (!forceRecreate && shouldBeShown == isShown) return
 
-    if (state) {
+    if (diffViewer != null) {
+      previewDiffSplitter.secondComponent = null
+      Disposer.dispose(diffViewer!!.disposable)
+      diffViewer = null
+    }
+
+    if (shouldBeShown) {
       val newDiffViewer = createViewer()
       val component = newDiffViewer.component
       previewDiffSplitter.secondComponent = component
@@ -75,11 +86,6 @@ internal abstract class FrameDiffPreview(uiProperties: VcsLogUiProperties,
                                         defaultMinimumSize.height.coerceAtMost((actionButtonSize.height * 1.5f).roundToInt()))
       diffViewer = newDiffViewer
     }
-    else {
-      previewDiffSplitter.secondComponent = null
-      Disposer.dispose(diffViewer!!.disposable)
-      diffViewer = null
-    }
   }
 
   private fun changeDiffPreviewOrientation(bottom: Boolean) {