Don't render children of collapsed blocks

[moniika]

The basics

• I branched from develop
• My pull request is against develop
• My code follows the style guide

The details

Resolves

Part of #4229

Proposed Changes

• Sets rendered state of children of collapsed blocks to false, so they are not re-rendered when the block is moved.
• Checks if child is rendered before recursively calling updateDisabled on children in updateDisabled.

Reason for Changes

Improves performance.

Test Coverage

Tested scenario descibed in #4229 and saw improvement in performance while testing with chrome performance tool.

Tested that issues #3784 was still fixed.

Tested issue #1967 in playground using xml:

<xml xmlns="https://developers.google.com/blockly/xml">
  <block type="controls_repeat_ext" x="88" y="138">
    <value name="TIMES">
      <shadow type="math_number">
        <field name="NUM">10</field>
      </shadow>
    </value>
    <statement name="DO">
      <block type="text_print">
        <value name="TEXT">
          <shadow type="text">
            <field name="TEXT">already here 1</field>
          </shadow>
        </value>
        <next>
          <block type="text_print">
            <value name="TEXT">
              <shadow type="text">
                <field name="TEXT">already here 2</field>
              </shadow>
            </value>
          </block>
        </next>
      </block>
    </statement>
  </block>
  <block type="text_print" x="88" y="288">
    <value name="TEXT">
      <shadow type="text">
        <field name="TEXT">connected while collapsed</field>
      </shadow>
    </value>
  </block>
</xml>

And repro code:

  var ws = Blockly.getMainWorkspace();
  var blocks = ws.getTopBlocks();
  blocks[0].setCollapsed(true);
  blocks[0].getInput('DO').connection.connect(blocks[1].previousConnection);
  // Check that attached block is hidden/not rendered
  blocks[0].setCollapsed(false);
  // Check that all blocks are un-hidden/rendered

Tested on:

• Desktop Chrome

Additional Information

n/a

[BeksOmega]

I think I might have changed this because of #1967 but I can't exactly remember.

[moniika]

I'm worried about whether this may have unintended side effects.

[BeksOmega]

I think it looks good! Because if the block is top-level it should definitely be visible right? As long as the nested disconnection test is passing it should be fine.

I'm going to tag this with #4288 though cuz I know that .rendered is kinda crazy wrt collapsed blocks.