autocomplete - HOME and END keys not working

[mxii]

Bug, feature request, or proposal:

I would like to use those keys as "normal" to navigate through my input string..
Like "shift + POS1" will select all.. :)

What is the expected behavior?

Maybe behavior of those keys could be configured?!

What is the current behavior?

Key will only be used to navigate through autocomplete-results

What are the steps to reproduce?

.. should be clear ..

What is the use-case or motivation for changing an existing behavior?

Better usability.
If i want to clear an input field, i will always press "shift + pos1" .. but now its not working anymore! =/
I would guess I am not the only one doing it like this..

Which versions of Angular, Material, OS, browsers are affected?

angular4, material.beta2

Is there anything else we should know?

No, thanks! :)

[crisbeto]

For reference, POS1 is the Home key on German keyboards.

[jefersonestevo]

+1

As angularjs autocomplete does allow to use these keys on the input, I agree that this should work on this component too.

[jefersonestevo]

@crisbeto @jelbourn I was looking to implement this, and I think the implementation here should consider the following paths:

• If the user press Shift+Home or Shift+End, it will select the whole text, as a normal input field does
• If there are only one or none option available, the Home and End key should behave like the input text field (changing the cursor to the beggining and end of the input field)

Both of these behaviours can be achieved by some conditional tests on the onKeydown method of ListKeyManager, but as this component is used in multiple components, If I put some code in it, it may break some other components behaviour. What may be done here is to add a second parameter (optional) to the onKeydown method to "decide" if the event.preventDefault() should be called or not. But I don't really know if it's the best way to implement this.

Example (just a simple conditional that may be extracted to a callback):

  onKeydown(event: KeyboardEvent): void {
    let shouldPreventDefault: boolean = true;
    switch (event.keyCode) {
      case DOWN_ARROW:
        this.setNextItemActive();
        break;
      case UP_ARROW:
        this.setPreviousItemActive();
        break;
      case HOME:
        this.setFirstItemActive();
        shouldPreventDefault = !event.shiftKey && this._items.length > 1;
        break;
      case END:
        this.setLastItemActive();
        shouldPreventDefault = !event.shiftKey && this._items.length > 1;
        break;
      case TAB:
        // Note that we shouldn't prevent the default action on tab.
        this._tabOut.next(null);
        return;
      default:
        return;
    }

    if (shouldPreventDefault) {
      event.preventDefault();
    }
  }

It'll really be nice if you can offer some guidance on the best way to implement this.

[jonbrock]

I've also been looking at this. There is some special handling done in autocomplete-trigger.ts already, so I added a check to see if the panel is actually open and if the shift key is being pressed. In my testing this works pretty intuitively. However, I'm not sure what the desired behavior is if home or end is pressed while the panel is closed.

  _handleKeydown(event: KeyboardEvent): void {
    if (this.activeOption && event.keyCode === ENTER) {
      this.activeOption._selectViaInteraction();
      event.preventDefault();
    } else {
      const prevActiveItem = this.autocomplete._keyManager.activeItem;
      const isArrowKey = event.keyCode === UP_ARROW || event.keyCode === DOWN_ARROW;

      if (isArrowKey) {
        this.openPanel();
      }
      
      // Only intercept keys if the panel is open and the shift key is not being used.
      if (this.panelOpen && !event.shiftKey) {
        this.autocomplete._keyManager.onKeydown(event);
      }

      Promise.resolve().then(() => {
        if (isArrowKey || this.autocomplete._keyManager.activeItem !== prevActiveItem) {
          this._scrollToOption();
        }
      });
    }
  }

[wulfsberg]

Please don't hijack the HOME and END with any special rules in special cases; simply let them work as they do in normal text editing.
If you are dead set on making special rules in some cases, please allow for a configurable opt-out.

I am very used to going back and editing input fields in complex searches, and having that sometimes be "randomly" blocked would be very surprising and frustrating.

[jefersonestevo]

@jonbrock your solution is really good and simple.

The only point that I can see that maybe be a problem is that the ListKeyManager also handles the TAB key. If the user press the Shift+TAB key (while the panel is open), the autocomplete-trigger will not fire the panelClosingActions event and someone that listen to this event will not be notified that the panel has been closed.

Of course we can handle this with:

     if (event.keyCode === TAB || (this.panelOpen && !event.shiftKey)) {
        this.autocomplete._keyManager.onKeydown(event);
      }

But I don't know if it's a good idea to the autocomplete-trigger to know that much of the implementation of the ListKeyManager (If the ListKeyManager implementation changes we may need to change the autocomplete-trigger implementation too).

If the material team think this is ok we can totally go this way.