Don't crash on invalid numbers.

Change-Id: I5c1bff5733c5db5f411c2827177b0c1efa1e120e
Fixes: 28756890

src/com/android/settings/display/DensityPreference.java

@@ -19,6 +19,7 @@ import android.content.res.Resources;
 import android.text.InputType;
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
+import android.util.Slog;
 import android.view.Display;
 import android.view.View;
 import android.widget.EditText;
@@ -27,6 +28,7 @@ import com.android.settings.R;
 import com.android.settingslib.display.DisplayDensityUtils;
 
 public class DensityPreference extends CustomEditTextPreference {
+    private static final String TAG = "DensityPreference";
 
     public DensityPreference(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ -62,6 +64,7 @@ public class DensityPreference extends CustomEditTextPreference {
     @Override
     protected void onDialogClosed(boolean positiveResult) {
         if (positiveResult) {
+            try {
                 final Resources res = getContext().getResources();
                 final DisplayMetrics metrics = res.getDisplayMetrics();
                 final int newSwDp = Math.max(Integer.parseInt(getText()), 320);
@@ -69,6 +72,10 @@ public class DensityPreference extends CustomEditTextPreference {
                 final int newDensity = DisplayMetrics.DENSITY_MEDIUM * minDimensionPx / newSwDp;
                 final int densityDpi = Math.max(newDensity, 120);
                 DisplayDensityUtils.setForcedDisplayDensity(Display.DEFAULT_DISPLAY, densityDpi);
+            } catch (Exception e) {
+                // TODO: display a message instead of silently failing.
+                Slog.e(TAG, "Couldn't save density", e);
+            }
         }
     }
 }