feat(scheduler): remove frame task queue after

Reduce API surface. Use cases that were solved by `after` frame tasks
can be easily solved with a new `afterUpdate()` task queue.

BREAKING CHANGE: `currentFrameAfter()` and `nextFrameAfter()` functions
were removed.

documentation/advanced/scheduler.md

@@ -21,23 +21,20 @@ is looking like this:
 4. Update dirty components.
 5. Check that `write` tasks queue is empty, otherwise go to step 3.
 6. Check that `read` tasks queue is empty, otherwise go to step 2.
-7. Execute `after` tasks until after task queue is empty.
-8. Execute `afterUpdate` tasks once per frame.
+7. Execute `afterUpdate` tasks once per frame.
 
 There are three functions to add tasks into different task queues in the current frame:
 
 ```ts
 function currentFrameRead(task: () => void): void;
 function currentFrameWrite(task: () => void): void;
-function currentFrameAfter(task: () => void): void;
 ```
 
 And three functions for the next frame:
 
 ```ts
 function nextFrameRead(task: () => void): void;
 function nextFrameWrite(task: () => void): void;
-function nextFrameAfter(task: () => void): void;
 ```
 
 ## beforeUpdate / afterUpdate

packages/ivi-scheduler/src/index.ts

@@ -28,10 +28,6 @@ const enum FrameTasksGroupFlags {
    * Group contains "read" tasks".
    */
   Read = 1 << 2,
-  /**
-   * Group contains "after" tasks.
-   */
-  After = 1 << 3,
 }
 
 interface TaskList {
@@ -74,18 +70,13 @@ interface FrameTasksGroup {
    * Read DOM task queue.
    */
   r: TaskList;
-  /**
-   * Tasks that should be executed when all other frame tasks are finished.
-   */
-  a: TaskList;
 }
 
 function createFrameTasksGroup(): FrameTasksGroup {
   return {
     f: 0,
     w: createTaskList(),
     r: createTaskList(),
-    a: createTaskList(),
   };
 }
 
@@ -306,12 +297,6 @@ const _handleNextFrame = catchError((time: number) => {
 
   runRepeatableTasks(_afterUpdate);
 
-  // Perform tasks that should be executed when all DOM ops are finished.
-  while ((frame.f & FrameTasksGroupFlags.After)) {
-    frame.f ^= FrameTasksGroupFlags.After;
-    run(frame.a);
-  }
-
   if (_autofocusedElement !== null) {
     (_autofocusedElement as HTMLElement).focus();
     _autofocusedElement = null;
@@ -334,11 +319,6 @@ function addFrameTaskRead(frame: FrameTasksGroup, task: () => void): void {
   frame.r.a.push(task);
 }
 
-function addFrameTaskAfter(frame: FrameTasksGroup, task: () => void): void {
-  frame.f |= FrameTasksGroupFlags.After;
-  frame.a.a.push(task);
-}
-
 export function nextFrameUpdate(): void {
   requestNextFrame();
   addFrameTaskUpdate(_nextFrame);
@@ -354,11 +334,6 @@ export function nextFrameRead(task: () => void): void {
   addFrameTaskRead(_nextFrame, task);
 }
 
-export function nextFrameAfter(task: () => void): void {
-  requestNextFrame();
-  addFrameTaskAfter(_nextFrame, task);
-}
-
 export function currentFrameUpdate(): void {
   if (_flags & SchedulerFlags.CurrentFrameReady) {
     addFrameTaskUpdate(_currentFrame);
@@ -383,14 +358,6 @@ export function currentFrameRead(task: () => void): void {
   }
 }
 
-export function currentFrameAfter(task: () => void): void {
-  if (_flags & SchedulerFlags.CurrentFrameReady) {
-    addFrameTaskAfter(_currentFrame, task);
-  } else {
-    nextFrameAfter(task);
-  }
-}
-
 /**
  * triggerNextFrame triggers an update for the next frame.
  */

packages/ivi-test-scheduler/src/index.ts

@@ -28,10 +28,6 @@ const enum FrameTasksGroupFlags {
    * Group contains "read" tasks".
    */
   Read = 1 << 2,
-  /**
-   * Group contains "after" tasks.
-   */
-  After = 1 << 3,
 }
 
 /**
@@ -53,18 +49,13 @@ interface FrameTasksGroup {
    * Read DOM task queue.
    */
   read: (() => void)[] | null;
-  /**
-   * Tasks that should be executed when all other frame tasks are finished.
-   */
-  after: (() => void)[] | null;
 }
 
 function createFrameTasksGroup(): FrameTasksGroup {
   return {
     flags: 0,
     write: null,
     read: null,
-    after: null,
   };
 }
 
@@ -220,11 +211,6 @@ function addFrameTaskRead(frame: FrameTasksGroup, task: () => void): void {
   frame.read = append(frame.read, task);
 }
 
-function addFrameTaskAfter(frame: FrameTasksGroup, task: () => void): void {
-  frame.flags |= FrameTasksGroupFlags.After;
-  frame.after = append(frame.after, task);
-}
-
 export function nextFrameUpdate(): void {
   requestNextFrame();
   addFrameTaskUpdate(_nextFrame);
@@ -240,11 +226,6 @@ export function nextFrameRead(task: () => void): void {
   addFrameTaskRead(_nextFrame, task);
 }
 
-export function nextFrameAfter(task: () => void): void {
-  requestNextFrame();
-  addFrameTaskAfter(_nextFrame, task);
-}
-
 export function currentFrameUpdate(): void {
   if ((_flags & SchedulerFlags.CurrentFrameReady) !== 0) {
     addFrameTaskUpdate(_currentFrame);
@@ -269,14 +250,6 @@ export function currentFrameRead(task: () => void): void {
   }
 }
 
-export function currentFrameAfter(task: () => void): void {
-  if ((_flags & SchedulerFlags.CurrentFrameReady) !== 0) {
-    addFrameTaskAfter(_currentFrame, task);
-  } else {
-    nextFrameAfter(task);
-  }
-}
-
 export function runMicrotasks(): void {
   if ((_flags & SchedulerFlags.MicrotaskPending) !== 0) {
     while (_microtasks.length > 0) {
@@ -368,17 +341,6 @@ export function triggerNextFrame(time?: number): void {
 
       runRepeatableTasks(_afterUpdate);
 
-      // Perform tasks that should be executed when all DOM ops are finished.
-      while ((frame.flags & FrameTasksGroupFlags.After) !== 0) {
-        frame.flags ^= FrameTasksGroupFlags.After;
-
-        tasks = frame.after!;
-        frame.after = null;
-        for (i = 0; i < tasks.length; ++i) {
-          tasks[i]();
-        }
-      }
-
       if (_autofocusedElement !== null) {
         (_autofocusedElement as HTMLElement).focus();
         _autofocusedElement = null;