A GUI Framework developing full screen apps using FullScreenUI API in SL4A
FullScreenWapper2 is a GUI Framework for developing full screen apps using the FullScreenUI API functions provided by SL4A in Python. This lets you design a look & feel similar to Android Java apps using the same XML Layouts and let you respond to View events.
It is a significant (non-backward compatible) enhancement over FullScreenWrapper that attempts to make programming using FullScreenUI as simple as programming in standard GUI Frameworks.
Update: A working Python3 compatible version is now available - could do with more testing.
- An FullScreenWrapper2App class that manages the eventloop & a layout stack enabling easy parent->child->parent transitions
- EventHandler classes with event-matching functions pre-built for standard View events like click,itemclick(ListView) and key
- Device Sensors & other similar SL4A/Custom events can also be caught & managed using the same eventloop + EventHandler class
- Object like access to a layout's views and properties (ie. MainLayout.views.txt_label.background = "#FFAA00AA")
You can find FullScreenWrapper2 files under the sl4atools directory in the Python for Android repository.
- fullscreenwrapper2.py is the main file you need to import
- Update: A working Python3 compatible version is now available - could do with more testing.
- API Docs generated from docstrings are available
- The following FullScreenWrapper2 examples are available
- Simple Demo to show basic usage of the Framework
- Gyroscope Sensor tilting example to show how FullScreenWrapper2 EventHandler classes can be used to catch SL4A events & use them in your User Interface
- A Full App (a calorie counter) that has parent & child layouts, resources & layouts being loaded from files, database access etc.
- A zip file with everything is available
First place fullscreenwrapper2.py in the same folder as your script. You start by importing everything from fullscreenwrapper2 & inheriting a class for your own layout from the Layout class and calling init function of Layout using super keyword with the XML Layout (string) and the Screen Title (string).
from fullscreenwrapper2 import *
class DemoLayout(Layout):
def __init__(self):
super(DemoLayout,self).__init__(xmldata,"FullScreenWrapper Demo")The on_show() function is very important as your views become accessible through the FullScreenWrapper2 framework ONLY AFTER on_show() is called by the framework. This is the place where you initialize / set the values of your views & setup event handlers. If you're having parent->child layouts, on_show() is also called when a child layout closes & the parent layout comes back on.
Views & their properties can be accessed via Layout.views.view_id.property. In the example below, we're setting the background color - most simple properties should work without a hitch.
Both the Layout & the individual Views can have events associated with them. You would typically use click_EventHandler & itemclick_EventHandlers (for ListView) with Views. The init for these take the View itself & an event handler function reference to call when the event occurs as parameters.
You would typically associate key_EventHandler with the layout itself. The init for key_EventHandler takes a key_match_id (defaults to "4" which is the back key), a view (defaults to None) and an event handler function reference as parameters.
def on_show(self):
self.add_event(key_EventHandler(handler_function=self.close_app))
self.views.but_change.add_event(click_EventHandler(self.views.but_change,
self.change_color))
self.views.but_exit.add_event(click_EventHandler(self.views.but_exit, self.close_app))
self.views.txt_colorbox.background="#ffffffff"For Sensor events like Gyroscope, you can directly use the EventHandler class - just set
You can access a view's properties Layout.views.view_id.property
def on_show(self):
self.add_event(key_EventHandler(handler_function=self.close_app))
self.views.but_change.add_event(click_EventHandler(self.views.but_change,
self.change_color))
self.views.but_exit.add_event(click_EventHandler(self.views.but_exit, self.close_app))
self.views.txt_colorbox.background="#ffffffff"The on_close() is mainly allow you to save state before a layout dissappears if needed. You can have pass as the only statement.
def on_close(self):
passThe restriction of views becoming accessible only after the framework calls on_show() of a layout is because of the the way FullScreenUI works. You need to show a layout first before you can access its views. FullScreenWrapper2 uses Android.fullGetProperty() to find out which views contain an "id" and are available for access and creates & populates View objects in each layout's views collection. These View objects let you associate events with them & allow you to access properties through SL4A reflection using setattr() and getattr(). Layouts handle their events through a special view added to the views collection.
The event handler function definition signature should be as follows:
def event_handler_function(self,view,event):
Each event handler is passed a reference to the view with which the event is associated (can be
None) & the SL4A event data obtained from Android.eventPoll().result0. In the example below, every
time a button on screen is pressed, the textbox changes to a random color background.
```python
def close_app(self,view,event):
FullScreenWrapper2App.exit_FullScreenWrapper2App()
def change_color(self,view, event):
colorvalue =
"#ff"+self.get_rand_hex_byte()+self.get_rand_hex_byte()+self.get_rand_hex_byte()
self.views.txt_colorbox.background=colorvalue
def get_rand_hex_byte(self):
j = random.randint(0,255)
hexrep = hex(j)[2:]
if(len(hexrep)==1):
hexrep = '0'+hexrep
return hexrep Once your layout class is setup, in your main function, initialize the framework first with Android.Android(). Then show the layout using FullScreenWrapper2App.show_layout() and initiate the eventloop().
if __name__ == '__main__':
droid = android.Android()
random.seed()
FullScreenWrapper2App.initialize(droid)
FullScreenWrapper2App.show_layout(DemoLayout())
FullScreenWrapper2App.eventloop()The full code from above example is shown here to show how simple it all is. The full source code including the XML Layout is also availble.
For simple XML layouts, you can just define layout in a string variable in your module. However, as your apps become more complex, you may want to load from sdcard files or even the internet.
import android, random
from fullscreenwrapper2 import *
class DemoLayout(Layout):
def __init__(self):
super(DemoLayout,self).__init__(xmldata,"FullScreenWrapper Demo")
def on_show(self):
self.add_event(key_EventHandler(handler_function=self.close_app))
self.views.but_change.add_event(click_EventHandler(self.views.but_change,
self.change_color))
self.views.but_exit.add_event(click_EventHandler(self.views.but_exit, self.close_app))
self.views.txt_colorbox.background="#ffffffff"
def on_close(self):
pass
def close_app(self,view,event):
FullScreenWrapper2App.exit_FullScreenWrapper2App()
def change_color(self,view, event):
colorvalue =
"#ff"+self.get_rand_hex_byte()+self.get_rand_hex_byte()+self.get_rand_hex_byte()
self.views.txt_colorbox.background=colorvalue
def get_rand_hex_byte(self):
j = random.randint(0,255)
hexrep = hex(j)[2:]
if(len(hexrep)==1):
hexrep = '0'+hexrep
return hexrep
if __name__ == '__main__':
droid = android.Android()
random.seed()
FullScreenWrapper2App.initialize(droid)
FullScreenWrapper2App.show_layout(DemoLayout())
FullScreenWrapper2App.eventloop()This document is from "FullScreenWrapper2 Framework" by srinathd...@gmail.com is licensed under Creative Commons Attribution 3.0 Unported License.
Modifications by Shimoda
- Format to markdown.
This work is open source & licensed under a Creative Commons Attribution 3.0 Unported License. This is a very permissive license & you're pretty much free to use & modify any way you want (including commercial use) with attribution.
