Introduce TizenViewEventHandlerDelegate and rework FlutterDesktopViewResize

[bbrto21]

• TizenViewEventHandlerDelegate only provides a limited interface for delegating event handling.
• FlutterDesktopViewResize should work on all types of views.
• Implementations of TizenViewBase::SetGeometry only manipulate top-level raw object such as window, container.
  other components in the view are manipulated on a resize callback.
• window channel use SetGeometry normally.

Signed-off-by: Boram Bae boram21.bae@samsung.com

[JSUYA]

Please check my comments

[JSUYA]

Directly accessing self->container_ and setting value within this callback and calling EvasObjectResizeWithMinMaxHint goes against the delegation you talked about so far.

If the container and image need to resize, call sefl->view_delegate_->Resize(??) and handle the appropriate process inside.

[JSUYA]

For further explanation, I'm leaving my opinions from the offline meeting here.

First of all, I don't think it's appropriate to directly call container_ and image_'s evas object resize api in resize callback.
Since the declaration of the Resize callback function is in TizenViewElementary, it can look like calling an internal member. But I don't think that. I think that the Resize that occurred on TizenViewXXXX should be delegated to FlutterTizenView and FlutterTizenView should call Resize of TizenViewXXXX in a consistent way.
That's why I think we should delegate the behavior through appropriately modified FlutterTizenView::OnResize() or additional FlutterTizenView::XXXX, and that method should call setGeoemtry or a function that resizes container_ and image_ through the appropriate TizenView::XXX method.

Secondary, FlutterTizenView::Resize only changes container_. As a result, FlutterTizenView::Resize depends on the callback of the container_.
For example, If we need pressKey API for (Elm)FlutterView, we can create FlutterDesktopViewPressKeyXXX() API and add FlutterTizenView::PressKey() to it.
Then, add the TizenViewElemetary's presskey to call it again, or occure to key event through evas_object_event_callback_call() of event_layer_ and rely on that callback.
This is unnatural and I think we can just call OnKey() directly from FlutterTizenView::PressKey().
The same goes for Resize. In FlutterTizenView::Resize, OnResize is called immediately, and OnResize is just by calling the appropriate resize method for the engine and flutterview.
(Of course, additional work is required, such as preventing duplicate calls by checking the size in the callback.)
At this time, the evas event API calls of the container_ and 'image_` of the callback function should be separated into separate functions.

My opinion is complicated and can be wrong. This opinion does not affect the actual behavior. And it can be applied later through additional refactoring.(If you need).
Please don't feel pressured