View-Framework:-BaseView.md

Overview

This is the base view responsible for mixing in functions for focus management, key handling and providing the main framework. It light enough for use as a component; but not recommended for use in RowLists, Grids and other aggregate views which are expected to have a large amount of view items.

This view is intended to be extended by Components, which in turn are aggregates of views; but not whole screens.

BaseView fields

• isInitialized - indicates if initialize has yet been called
• isShown, true if the view is on screen
• name, useful for logging
• state, contains the state of the current view none|initialized|destroyed

BaseView methods

• initialize - must be called to start the view machinery

BaseView abstract methods

You can override these methods to safely drive your application behavior

• applyStyle(styles, localizations, assets) - will be called when the view is initialized, so it can apply required styles, etc
• initialize(args) - called when the view has been initialized
• onFirstShow - called the first time a view is shown
• onShow - called when a view is shown
  • Note that a view cannot be shown if it is not initialized. This method will be called immediately for a visible view, when initialize is invoked
• onHide - called when a view is hidden

In addition you can override the methods in KeyMixin:

• isAnyKeyPressLocked() - returns true if any key press is locked - the default implementation returns the value of m.isKeyPressLocked
• isCapturingAnyKeyPress(key), return true if the key key is captured

Override the following, to return true, if the applicable key is captured

• onKeyPressDown()
• onKeyPressUp()
• onKeyPressLeft()
• onKeyPressRight()
• onKeyPressBack()
• onKeyPressOption()
• onKeyPressOK()

Also, BaseView allows entry points for overriding abstract methods from FocusMixin

• onGainedFocus(isSelfFocused)
• onLostFocus()