How to save the current state of switches in Android Studio? - android-activity

Question

I know very little about programming. I downloaded Android Studio and started tinkering with it. I tried to make the app that they put on the tutorial and it worked. However I tried to add more functionality to it and I've failed so far. Excuse me if you see unnecessary junk on my code, I'm just kinda trying everything at first and I do feel a little misguided.
Anyways, onto the question. I have a Switch (id:toggle_text) with an OnClick action (change_font). When the switch is toggled it should change the font size of a different activity through intent1. Currently not only does it not send the font size variable (the variable keeps the default value you put on getIntExtra), but now that I tried to add the ability to save the current state it just shows errors. Here's the code:
package com.example.myfirstapp;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.ToggleButton;
import android.widget.TextView;
import static com.example.myfirstapp.R.id.toggle_text;
import static com.example.myfirstapp.R.string.change_font;
public class ShowAnOption extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_an_option);
SharedPreferences sharedPrefs = getSharedPreferences("com.example.xyz", MODE_PRIVATE);
toggle.setChecked(sharedPrefs.getBoolean("NameOfThingToSave", true));
}
public void change_font(View v) {
int fssize;
if (toggle.isChecked())
{
SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
editor.putBoolean("NameOfThingToSave", true);
editor.commit();
fssize=20;
}
else
{
SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
editor.putBoolean("NameOfThingToSave", false);
editor.commit();
fssize=40;
}
Intent intent1 = new Intent (getBaseContext(), DisplayMessageActivity.class);
intent1.putExtra("Font_Size", fssize);
}
}
It says "cannot resolve symbol toggle" on toggle.setChecked() and the if statement. What can I do to fix this? Also, why does it not get sent to the other activity? Here's the code on the other activity:
package com.example.myfirstapp;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.TextView;
public class DisplayMessageActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
Intent intent = getIntent();
Intent intent1 = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
int Font_Size = intent1.getIntExtra("Font_Size",50);
TextView textView = new TextView(this);
textView.setTextSize(Font_Size);
textView.setText(message);
ViewGroup layout = (ViewGroup) findViewById(R.id.activity_display_message);
layout.addView(textView);
}
}
Thanks and sorry for the long read. If there's anything else that needs to be known let me know and I'll gladly show.

Answer 1

We did not try to change the font size but here is how to use the switch widget.
Our design is two activities MainActivity and SwitchActivity we changed a CheckBox from unchecked to checked The switch is on the MainActivity code below
setOnCheckedChangeListener();
private void setOnCheckedChangeListener() {
swAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked) {
Toast.makeText(MainActivity.this, "Switch On", Toast.LENGTH_SHORT).show();
Intent intentSP = new Intent(MainActivity.this, SwitchActivity.class );
Bundle extras = new Bundle();
extras.putString("FONT","true" );
intentSP.putExtras(extras);
startActivity( intentSP );
} else {
Toast.makeText(MainActivity.this, "Switch Off", Toast.LENGTH_SHORT).show();
}
}
});
}
Now in the SwitchAcvity we capture the value from the intent and fire the method
doWhat()
Intent intentSP = getIntent();
Bundle bundle = intentSP.getExtras();
tORf = bundle.getString("FONT");
doWhat(null);
And here is the doWhat method
public void doWhat(View view){
if(tORf.equals("true")){
chkBoxOne.setChecked(true);
}else {
Toast.makeText( SwitchActivity.this, "NOT TRUE", Toast.LENGTH_LONG ).show();
}
}