Improve DropdownContainer

[elazutkin]

The TimePicker? widget requires up to 3 clicks to set time: one to select an hour, one to select AM/PM, and one to select minutes. It makes the DropdownTimePicker? cumbersome to use: after every click it closes, and has to be re-opened to select a next time component. (See #1872 for merging DatePicker? and TimePicker?, which will require the proposed functionality.)

The DropdownContainer? should support a special mode of operation specified by a separate parameter. After opening the container it should watch for following events:

1. User pressed Esc button => close it.
2. User clicked outside the container => close it.
3. Containing widget requested to close the container (e.g., when user clicked a special "close" button, or made her selection) => close it.
4. (optional) If a cursor is inside the container, close it when the cursor goes outside.

[peller]

let's also find a standard mechanism to clear out the data, if we decide that's a requirement, preferably in a language neutral way. (To replace the "any" in the current time picker)

[peller]

Even with redesign of the timepicker (#599) similar issues may remain. It might be useful to have another gesture such that the user is able to click around the widget and see the results before making a selection.

[bill]

I agree that TimePicker? is painful to use. [ We've basically gotten rid of DropdownContainer? in dijit 0.9. You call PopupManager? to display a dropdown, and connect to onValueChanged. It's up to the "parent" widget about whether or not to close the dropdown on value selected. So I'm going to close this bug (about DropdownContainer?) because I think it's resolved.