using-python-to-update-widget.md

Using Python to Make Changes in Home Screen widget

Prerequisite

• You should have gone through README.md <-- Important

Required Things

• A App Widget Provider java file, With defined Class even if it's empty, How to add

Prerequisite Steps in README.md

Example - Changing Text

Actual Widget

• Important to mark widget_text which is the Text id, would be used to select later

Stored in: res/layout/simple_widget.xml This a simple widget with a text

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:padding="10dp"
    android:background="#FFFFFF"
    android:gravity="center"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/widget_text"
        android:text="Loading..."
        android:textSize="18sp"
        android:textColor="#000"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

An App Widget Provider

path: src/SimpleWidget.java.

• Can be Empty Since we using python to make Changes
• Useful For receiving event like Taps and Swipes

package org.wally.waller; // Change here from buildozer.spec package.domain+package.name

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.Context;
import android.widget.RemoteViews;

import org.wally.waller.R; // Change here from buildozer.spec package.domain+package.name
import android.app.PendingIntent;
import android.content.Intent;

public class SimpleWidget extends AppWidgetProvider {

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        for (int appWidgetId : appWidgetIds) {

            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.simple_widget);

            // Set text
            views.setTextViewText(R.id.widget_text, "Hello frm Java!");

            // Update widget
            appWidgetManager.updateAppWidget(appWidgetId, views);
        }
    }
}

Create an xml containing the info about the widget.

Like: size, preview icon and others
path: res/xml/widgetproviderinfo.xml

<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="120dp"
    android:minHeight="60dp"
    android:updatePeriodMillis="1800000"
    android:initialLayout="@layout/simple_widget"

    android:resizeMode="horizontal|vertical"
    android:widgetCategory="home_screen">
</appwidget-provider>

Automate injecting Receiver in XML

[!IMPORTANT]
This is where we link App Widget Provider to Actual Widget xml
And Provide Info about widget too.

from pathlib import Path
from pythonforandroid.toolchain import ToolchainCL


def after_apk_build(toolchain: ToolchainCL):
    manifest_file = Path(toolchain._dist.dist_dir) / "src" / "main" / "AndroidManifest.xml"
    text = manifest_file.read_text(encoding="utf-8")

    package = "org.wally.waller" # Change here to yours
    receiver_xml = f'''
    <receiver android:name="{package}.SimpleWidget"
              android:enabled="true"
              android:exported="false">
        <intent-filter>
            <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
        </intent-filter>
        <meta-data android:name="android.appwidget.provider"
               android:resource="@xml/widgetproviderinfo" />
    </receiver>
    '''

    if receiver_xml.strip() not in text:
        if "</application>" in text:
            text = text.replace("</application>", f"{receiver_xml}\n</application>")
            print("Receiver added")
        else: 
            print("Could not find </application> to insert receiver")
    else: 
        print("Receiver already exists in manifest")

    manifest_file.write_text(text, encoding="utf-8")
    print("Successfully_101: Manifest update completed successfully!")

Changing Text with Python

Things needed

• App Widget Provider Class Name, In our case SimpleWidget
• Widget File name, In our case simple_widget
• Text id, In our case widget_text

from jnius import autoclass

AppWidgetManager = autoclass('android.appwidget.AppWidgetManager')
ComponentName = autoclass('android.content.ComponentName')
RemoteViews = autoclass('android.widget.RemoteViews')
AndroidString = autoclass("java.lang.String")

context =  PythonActivity.mActivity.getApplicationContext()
resources = context.getResources()
package_name = context.getPackageName()
class_name = "SimpleWidget"
widget_file_name = "simple_widget"
text_id = "widget_text"
new_txt = "Hello Frm Python"

component = ComponentName( context, f'{package_name}.{class_name}' )
appWidgetManager = AppWidgetManager.getInstance(context)
ids = appWidgetManager.getAppWidgetIds(component) # In tests would be empty if Java file doesn't exist

text_layout_id = resources.getIdentifier(widget_file_name, "layout", package_name) # In tests would return "0" if layout doesn't exist
views = RemoteViews(package_name, text_layout_id)

title_id = resources.getIdentifier(text_id, "id", package_name) # In tests would return "0" if id doesn't exist
views.setTextViewText(title_id, AndroidString(new_txt))
appWidgetManager.updateAppWidget(ids, views)

For Questions: open_issue