Better connection handling and initial code for settings activity

app/src/main/java/de/rumpold/androiddsky/ui/SettingsActivity.java

@@ -0,0 +1,198 @@
+package de.rumpold.androiddsky.ui;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.Intent;
+import android.content.res.Configuration;
+import android.media.Ringtone;
+import android.media.RingtoneManager;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Bundle;
+import android.preference.ListPreference;
+import android.preference.Preference;
+import android.preference.PreferenceActivity;
+import android.preference.PreferenceFragment;
+import android.preference.PreferenceManager;
+import android.preference.RingtonePreference;
+import android.support.v7.app.ActionBar;
+import android.text.TextUtils;
+import android.view.MenuItem;
+
+import java.util.List;
+
+import de.rumpold.androiddsky.R;
+
+/**
+ * A {@link PreferenceActivity} that presents a set of application settings. On
+ * handset devices, settings are presented as a single list. On tablets,
+ * settings are split by category, with category headers shown to the left of
+ * the list of settings.
+ * <p>
+ * See <a href="http://developer.android.com/design/patterns/settings.html">
+ * Android Design: Settings</a> for design guidelines and the <a
+ * href="http://developer.android.com/guide/topics/ui/settings.html">Settings
+ * API Guide</a> for more information on developing a Settings UI.
+ */
+public class SettingsActivity extends AppCompatPreferenceActivity {
+
+    /**
+     * A preference value change listener that updates the preference's summary
+     * to reflect its new value.
+     */
+    private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
+        @Override
+        public boolean onPreferenceChange(Preference preference, Object value) {
+            String stringValue = value.toString();
+
+            if (preference instanceof ListPreference) {
+                // For list preferences, look up the correct display value in
+                // the preference's 'entries' list.
+                ListPreference listPreference = (ListPreference) preference;
+                int index = listPreference.findIndexOfValue(stringValue);
+
+                // Set the summary to reflect the new value.
+                preference.setSummary(
+                        index >= 0
+                                ? listPreference.getEntries()[index]
+                                : null);
+
+            } else if (preference instanceof RingtonePreference) {
+                // For ringtone preferences, look up the correct display value
+                // using RingtoneManager.
+                if (TextUtils.isEmpty(stringValue)) {
+                    // Empty values correspond to 'silent' (no ringtone).
+                    preference.setSummary(R.string.pref_ringtone_silent);
+
+                } else {
+                    Ringtone ringtone = RingtoneManager.getRingtone(
+                            preference.getContext(), Uri.parse(stringValue));
+
+                    if (ringtone == null) {
+                        // Clear the summary if there was a lookup error.
+                        preference.setSummary(null);
+                    } else {
+                        // Set the summary to reflect the new ringtone display
+                        // name.
+                        String name = ringtone.getTitle(preference.getContext());
+                        preference.setSummary(name);
+                    }
+                }
+
+            } else {
+                // For all other preferences, set the summary to the value's
+                // simple string representation.
+                preference.setSummary(stringValue);
+            }
+            return true;
+        }
+    };
+
+    /**
+     * Helper method to determine if the device has an extra-large screen. For
+     * example, 10" tablets are extra-large.
+     */
+    private static boolean isXLargeTablet(Context context) {
+        return (context.getResources().getConfiguration().screenLayout
+                & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
+    }
+
+    /**
+     * Binds a preference's summary to its value. More specifically, when the
+     * preference's value is changed, its summary (line of text below the
+     * preference title) is updated to reflect the value. The summary is also
+     * immediately updated upon calling this method. The exact display format is
+     * dependent on the type of preference.
+     *
+     * @see #sBindPreferenceSummaryToValueListener
+     */
+    private static void bindPreferenceSummaryToValue(Preference preference) {
+        if (preference == null) {
+            return;
+        }
+
+        // Set the listener to watch for value changes.
+        preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);
+
+        // Trigger the listener immediately with the preference's
+        // current value.
+        sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
+                PreferenceManager
+                        .getDefaultSharedPreferences(preference.getContext())
+                        .getString(preference.getKey(), ""));
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setupActionBar();
+    }
+
+    /**
+     * Set up the {@link android.app.ActionBar}, if the API is available.
+     */
+    private void setupActionBar() {
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            // Show the Up button in the action bar.
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean onIsMultiPane() {
+        return isXLargeTablet(this);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
+    public void onBuildHeaders(List<Header> target) {
+        loadHeadersFromResource(R.xml.pref_headers, target);
+    }
+
+    /**
+     * This method stops fragment injection in malicious applications.
+     * Make sure to deny any unknown fragments here.
+     */
+    protected boolean isValidFragment(String fragmentName) {
+        return PreferenceFragment.class.getName().equals(fragmentName)
+                || GeneralPreferenceFragment.class.getName().equals(fragmentName);
+    }
+
+    /**
+     * This fragment shows general preferences only. It is used when the
+     * activity is showing a two-pane settings UI.
+     */
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
+    public static class GeneralPreferenceFragment extends PreferenceFragment {
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+            addPreferencesFromResource(R.xml.pref_general);
+            setHasOptionsMenu(true);
+
+            // Bind the summaries of EditText/List/Dialog/Ringtone preferences
+            // to their values. When their values change, their summaries are
+            // updated to reflect the new value, per the Android Design
+            // guidelines.
+            bindPreferenceSummaryToValue(findPreference("agc_host"));
+            bindPreferenceSummaryToValue(findPreference("agc_port"));
+        }
+
+        @Override
+        public boolean onOptionsItemSelected(MenuItem item) {
+            int id = item.getItemId();
+            if (id == android.R.id.home) {
+                startActivity(new Intent(getActivity(), SettingsActivity.class));
+                return true;
+            }
+            return super.onOptionsItemSelected(item);
+        }
+    }
+}