Custom Settings to Fire off Shell Script

Question

So, I am working on a "custom settings" app for my android phone, and I am in need of a little help here....

Here's what I'd like to do... I'd like to be able to set a Preference in the /res/xml/file.xml that on tap fires off a shell script based on some value in the xml

So, say my Preference is:

<ListPreference android:key="dp_cleaner" android:title="My Cleaner" android:entries="@array/dp_cleaner_entries" android:entryValues="@array/dp_cleaner_entries_values" />

And the .smali method to fire off the shell scripts is

.method public static execRootCmdSilent(Ljava/lang/String;)I
# Contains all my code to fire it off...
.end method

Usage

:try_start_0
const-string v2, "THE_COMMAND"
invoke-static {v2}, Lcom/android/settings/ExecSH;->execRootCmdSilent(Ljava/lang/String;)I
:try_end_0
.catch Ljava/lang/Exception; {:try_start_0 .. :try_end_0} :catch_0

How could I populate my const-string from the tapped value in the list? I'm assuming that I would need to findPreference somehow via the key, but I don't know how I can pass the tapped value to the method....

Could it be something as simple as:

.class public Lcom/android/settings/ExecSH;
.super Lcom/android/settings/SettingsPreferenceFragment;
.source "ExecSH.java"

.implements Landroid/preference/Preference$OnPreferenceChangeListener;
.implements Landroid/preference/Preference$OnPreferenceClickListener;


# direct methods
.method public onPreferenceTreeClick(Landroid/preference/PreferenceScreen;Landroid/preference/Preference;)Z

    :try_start_0
    const-string v2, Landroid/preference/Preference;->findPreference(Ljava/lang/CharSequence;)Landroid/preference/Preference;

    invoke-static {v2}, Lcom/android/settings/ExecSH;->execRootCmdSilent(Ljava/lang/String;)I
    :try_end_0
    .catch Ljava/lang/Exception; {:try_start_0 .. :try_end_0} :catch_0

.end method

.method public static execRootCmdSilent(Ljava/lang/String;)I
#MY CODE
.end method

Answer 1

Your class needs to implement the Preference.OnPreferenceChangedListener interface and be set as your ListPreference's change listener. Your listener method will be passed the new value as a parameter, at which point you can pass that in to your execRootCmdSilent method.

The critical smali section is toward the bottom of the below files:

.method public onPreferenceChange(Landroid/preference/Preference;Ljava/lang/Object;)Z

    move-object v2, p2

    // there are some more moves here and a test, which is why we're shuffling registers

    move-object v3, v2

    invoke-virtual {v3}, Ljava/lang/Object;->toString()Ljava/lang/String;

    move-result-object v3

    invoke-static {v3}, Lsarbs/com/tinker/SettingsActivity;->execRootCmdSilent(Ljava/lang/String;)I

Basically, the p2 value is the second parameter being passed to the onPreferenceChange method (newValue). We move that into a local register, and then invoke-virtual the toString method on it. Move the result of that call into the v3 register, and then you can invoke-static your execRootCmdSilent method using that v3 register as the parameter.

The Java code I used to implement this:

package sarbs.com.tinker;

import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;

public class SettingsActivity extends PreferenceActivity implements Preference.OnPreferenceChangeListener {
    ListPreference mListPreference;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        addPreferencesFromResource(R.xml.pref_general);

        mListPreference = (ListPreference) findPreference("dp_cleaner");
        mListPreference.setOnPreferenceChangeListener(this);
    }

    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {
        if (preference == mListPreference) {
            execRootCmdSilent(newValue.toString());
        }
        return true;
    }

    public static int execRootCmdSilent(String str) {
        return 0;
    }
}

And the smali code it produced:

.class public Lsarbs/com/tinker/SettingsActivity;
.super Landroid/preference/PreferenceActivity;
.source "SettingsActivity.java"

# interfaces
.implements Landroid/preference/Preference$OnPreferenceChangeListener;


# instance fields
.field mListPreference:Landroid/preference/ListPreference;


# direct methods
.method public constructor <init>()V
    .registers 3

    .prologue
    .line 8
    move-object v0, p0

    .local v0, "this":Lsarbs/com/tinker/SettingsActivity;
    move-object v1, v0

    invoke-direct {v1}, Landroid/preference/PreferenceActivity;-><init>()V

    return-void
.end method

.method public static execRootCmdSilent(Ljava/lang/String;)I
    .registers 3

    .prologue
    .line 30
    move-object v0, p0

    .local v0, "str":Ljava/lang/String;
    const/4 v1, 0x0

    move v0, v1

    .end local v0    # "str":Ljava/lang/String;
    return v0
.end method


# virtual methods
.method protected onCreate(Landroid/os/Bundle;)V
    .registers 7

    .prologue
    .line 13
    move-object v0, p0

    .local v0, "this":Lsarbs/com/tinker/SettingsActivity;
    move-object v1, p1

    .local v1, "savedInstanceState":Landroid/os/Bundle;
    move-object v2, v0

    move-object v3, v1

    invoke-super {v2, v3}, Landroid/preference/PreferenceActivity;->onCreate(Landroid/os/Bundle;)V

    .line 15
    move-object v2, v0

    const v3, 0x7f030001

    invoke-virtual {v2, v3}, Lsarbs/com/tinker/SettingsActivity;->addPreferencesFromResource(I)V

    .line 17
    move-object v2, v0

    move-object v3, v0

    const-string v4, "dp_cleaner"

    invoke-virtual {v3, v4}, Lsarbs/com/tinker/SettingsActivity;->findPreference(Ljava/lang/CharSequence;)Landroid/preference/Preference;

    move-result-object v3

    check-cast v3, Landroid/preference/ListPreference;

    iput-object v3, v2, Lsarbs/com/tinker/SettingsActivity;->mListPreference:Landroid/preference/ListPreference;

    .line 18
    move-object v2, v0

    iget-object v2, v2, Lsarbs/com/tinker/SettingsActivity;->mListPreference:Landroid/preference/ListPreference;

    move-object v3, v0

    invoke-virtual {v2, v3}, Landroid/preference/ListPreference;->setOnPreferenceChangeListener(Landroid/preference/Preference$OnPreferenceChangeListener;)V

    .line 19
    return-void
.end method

.method public onPreferenceChange(Landroid/preference/Preference;Ljava/lang/Object;)Z
    .registers 8

    .prologue
    .line 23
    move-object v0, p0

    .local v0, "this":Lsarbs/com/tinker/SettingsActivity;
    move-object v1, p1

    .local v1, "preference":Landroid/preference/Preference;
    move-object v2, p2

    .local v2, "newValue":Ljava/lang/Object;
    move-object v3, v1

    move-object v4, v0

    iget-object v4, v4, Lsarbs/com/tinker/SettingsActivity;->mListPreference:Landroid/preference/ListPreference;

    if-ne v3, v4, :cond_12

    .line 24
    move-object v3, v2

    invoke-virtual {v3}, Ljava/lang/Object;->toString()Ljava/lang/String;

    move-result-object v3

    invoke-static {v3}, Lsarbs/com/tinker/SettingsActivity;->execRootCmdSilent(Ljava/lang/String;)I

    move-result v3

    .line 26
    :cond_12
    const/4 v3, 0x1

    move v0, v3

    .end local v0    # "this":Lsarbs/com/tinker/SettingsActivity;
    return v0
.end method