Back out "Pulls mount related code into its own method"

Summary:
Original commit changeset: 8607dd575d12

Original Phabricator Diff: D57967701

Differential Revision: D58823704

fbshipit-source-id: 4711eb917e3e0c475a32d8a1269dec6ccd01bc98

litho-core/src/main/java/com/facebook/litho/BaseMountingView.java

@@ -452,83 +452,71 @@ private void maybeMountOrNotifyVisibleBoundsChange(
       return;
     }
 
-    if (shouldPauseMountingWithVisibilityHintFalse()) {
-      return;
-    }
-
-    final Rect visibleRectToUse;
-    final boolean processVisibilityOutputs;
-    if (mTransientStateCount > 0 && hasTree() && isIncrementalMountEnabled()) {
-      // If transient state is set but the MountState is dirty we want to re-mount everything.
-      // Otherwise, we don't need to do anything as the entire BaseMountingView was mounted when
-      // the transient state was set.
-      if (!isMountStateDirty()) {
-        return;
-      } else {
-        visibleRectToUse = new Rect(0, 0, getWidth(), getHeight());
-        processVisibilityOutputs = false;
-      }
-    } else {
-      visibleRectToUse = actualVisibleRect;
-      processVisibilityOutputs = requestVisibilityEvents;
-    }
+    final boolean isDirtyMount = isMountStateDirty();
 
-    if (visibleRectToUse == null) {
-      mPreviousMountVisibleRectBounds.setEmpty();
-    } else {
-      mPreviousMountVisibleRectBounds.set(visibleRectToUse);
-    }
-
-    final boolean needsMount = isMountStateDirty() || mountStateNeedsRemount();
-    if (visibleRectToUse != null && !needsMount) {
-      layoutState.setShouldProcessVisibilityOutputs(processVisibilityOutputs);
-      Preconditions.checkNotNull(mMountState.getMountDelegate())
-          .notifyVisibleBoundsChanged(visibleRectToUse);
-    } else {
-      mount(visibleRectToUse, processVisibilityOutputs);
+    // If this is the first mount, we need to set the hasMounted flag on the TreeState.
+    final TreeMountInfo mountInfo = getMountInfo();
+    if (mountInfo != null && !mountInfo.hasMounted) {
+      mountInfo.isFirstMount = true;
+      mountInfo.hasMounted = true;
     }
-  }
 
-  private void mount(
-      final @Nullable Rect visibleRect, final boolean shouldProcessVisibilityEvents) {
+    mIsMounting = true;
 
-    final LayoutState layoutState = getCurrentLayoutState();
-    if (layoutState == null) {
-      return;
-    }
-    if (shouldPauseMountingWithVisibilityHintFalse()) {
-      return;
-    }
-
-    final boolean isMountStateDirty = isMountStateDirty();
     try {
 
-      // If this is the first mount, we need to set the hasMounted flag on the TreeState.
-      final TreeMountInfo mountInfo = getMountInfo();
-      if (mountInfo != null && !mountInfo.hasMounted) {
-        mountInfo.isFirstMount = true;
-        mountInfo.hasMounted = true;
+      if (shouldPauseMountingWithVisibilityHintFalse()) {
+        return;
+      }
+
+      final Rect visibleRectToUse;
+      final boolean processVisibilityOutputs;
+      if (mTransientStateCount > 0 && hasTree() && isIncrementalMountEnabled()) {
+        // If transient state is set but the MountState is dirty we want to re-mount everything.
+        // Otherwise, we don't need to do anything as the entire BaseMountingView was mounted when
+        // the transient state was set.
+        if (!isMountStateDirty()) {
+          return;
+        } else {
+          visibleRectToUse = new Rect(0, 0, getWidth(), getHeight());
+          processVisibilityOutputs = false;
+        }
+      } else {
+        visibleRectToUse = actualVisibleRect;
+        processVisibilityOutputs = requestVisibilityEvents;
       }
 
-      mIsMounting = true;
+      if (visibleRectToUse == null) {
+        mPreviousMountVisibleRectBounds.setEmpty();
+      } else {
+        mPreviousMountVisibleRectBounds.set(visibleRectToUse);
+      }
 
       Object onBeforeMountResult = onBeforeMount();
 
-      layoutState.setShouldProcessVisibilityOutputs(shouldProcessVisibilityEvents);
+      layoutState.setShouldProcessVisibilityOutputs(processVisibilityOutputs);
 
-      final RenderTree renderTree = layoutState.toRenderTree();
-      setupMountExtensions();
-      Preconditions.checkNotNull(mLithoHostListenerCoordinator);
-      mLithoHostListenerCoordinator.beforeMount(layoutState, visibleRect);
-      mMountState.mount(renderTree);
-      LithoStats.incrementComponentMountCount();
-      drawDebugOverlay(this, layoutState.getComponentTreeId());
+      final boolean needsMount = isMountStateDirty() || mountStateNeedsRemount();
+      if (visibleRectToUse != null && !needsMount) {
+        Preconditions.checkNotNull(mMountState.getMountDelegate())
+            .notifyVisibleBoundsChanged(visibleRectToUse);
+      } else {
+        // Generate the renderTree here so that any operations
+        // that occur in toRenderTree() happen prior to "beforeMount".
+        final RenderTree renderTree = layoutState.toRenderTree();
+        setupMountExtensions();
+        Preconditions.checkNotNull(mLithoHostListenerCoordinator);
+        mLithoHostListenerCoordinator.beforeMount(layoutState, visibleRectToUse);
+        mMountState.mount(renderTree);
+        LithoStats.incrementComponentMountCount();
+        drawDebugOverlay(this, layoutState.getComponentTreeId());
+      }
 
       onAfterMount(onBeforeMountResult);
       mIsMountStateDirty = false;
 
       final TreeState treeState = getTreeState();
-      if (isMountStateDirty && treeState != null) {
+      if (isDirtyMount && treeState != null) {
         treeState.recordRenderData(layoutState);
       }
     } catch (Exception e) {
@@ -538,7 +526,7 @@ private void mount(
         getMountInfo().isFirstMount = false;
       }
       mIsMounting = false;
-      if (isMountStateDirty) {
+      if (isDirtyMount) {
         onDirtyMountComplete();
       }
     }