The user interaction and the hierarchical view are all based on the touch mode. The touch mode is a very easy to use option and the previous user if has been on touch mode that will remain unchanged despite the user change. By making use of the android application development device you can exit the touch mode by selecting the widget and the trackball. But the shortest and easiest method to enter this mode is by touching on the button provided on the screen. As many modes other than the touch mode are available on the screen like the navigation mode, trackball mode there is lot of confusion prevailing in this perspective also.
The Android Application development UI toolkit is difficult to design due to the mechanism of interaction. As there are several options available for touch screen like the stylus, keyboard or the combination of both designing a neat and consistent android application development is challenging task. As the users have the freedom to choose which ever option they are comfortable in the Android development of touch mode is even more difficult. Much issue arises in such development and one such issue could be understood with the simple example of ApiDemos application. As per this the user will use the trackball and select the items or make use of the touch screen directly. If the user select any one of the items and then scrolls down then issues like if the selected item ahs to be cleared off or not and many others will crop up. As a result of this confusion the focus and selection option has been completely removed in the touch mode.
Though there is no focus mode in the touch mode however there is an advanced option called the focusable mode. In order to receive the text by the widgets and for filtering the list view the focusable option is available for easy navigation. Such mode is activated through the XML codes.
While making use of the touch modes do not use the focus and selection option at all. Be careful to sue the core applications and also consistent enough in applying the same.