Uploaded image for project: 'Minecraft (Bedrock codebase)'
  1. Minecraft (Bedrock codebase)
  2. MCPE-8590

Momentum Scrolling - Broken/Invalid Behavior; Needs Refactoring.

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Cannot Reproduce
    • None
    • 0.10.4, 0.11.0 Beta 6, 0.11.0 Beta 13, 0.11.0 Beta 14, 0.11.1, 0.13.0, 0.13.1, 0.14.0 Beta 1, 0.14.0 Beta 2
    • None
    • Survival
    • Confirmed
    • Phone - iOS - iPhone 6

      Problem:
      During bounce animation (the animation that occurs when the maximum scroll position is exceeded, which is when the scrollable contents are dragged down below their resting position/boundaries; typically 0px.), if the user attempts to invoke a reposition, the animation is cut off and the scroll position is immediately set to 0px.

      In short, whenever the user interacts with the scrolled contents while they are in the animated state, the scrolled contents need to immediately stop in place.

      For a visual representation of the bug;
      1. Launch Minecraft PE.
      2. Scroll to the top of a list.
      3. Pull the list down. (also note that the speed at which these contents scroll is not decelerated; which is a forgotten implementation.)
      4. Before the list returns to the initial position, tap the contents and watch the animation cut off.

      ---------------------------------------------------------------------

      UPDATE:

      To clarify, when the user creates any input into the scrolling (currently animating/moving) contents, the animation needs to cut and the contents need to stop in place. In Minecraft PE, this does not occur if the scrolled/scrolling contents go outside of the boundaries (rest positions). Instead, the contents spastically return to the rest position (typically 0px). This does not mean that the contents are supposed to continue animating back to the rest position and neglect user input. What it means is: if your finger is in contact with the display; the contents must stop in place (even if the contents are outside of the rest position), and if your finger is not in contact with the display, the contents must resume animating back to rest position (if you scrolled outside the rest position). Other than much need speed and momentum calibration, there are absolutely no bugs in scrolling within the scrollable boundaries, this bug only occurs if you're scrolling outside the boundaries. I suggest reading this comment a few times over.

            joshuasand0val Joshua Sandoval
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

              Created:
              Updated:
              Resolved:
              CHK: