Add a grid density setting

The grid cell size could only be changed by pinching the file list,
which is easy to miss and awkward to land on a particular size.

Add a density setting that writes the same stored value the pinch
gesture uses, so the two stay in step and neither overrides the other.
The options set how large the cells are rather than a fixed column
count, because a column count that suits a tablet leaves a phone with
cells too narrow to read.

The file list only read that value while creating its view, so a density
picked in the settings did not reach a list that was already open, and
the list then wrote its stale value back when it saved its state. Read
the value again on resume so the change takes effect on the way back.

Signed-off-by: David Sandquist <sandquist@gmail.com>

Author: sandbranch

app/src/main/java/com/owncloud/android/ui/activity/SettingsActivity.java

@@ -27,6 +27,7 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceActivity;
 import android.preference.PreferenceCategory;
@@ -966,6 +967,30 @@ private void setupGeneralCategory() {
                 return true;
             });
         }
+
+        setupGridDensityPreference();
+    }
+
+    /**
+     * The grid density shares its stored value with the pinch to zoom gesture in the file list,
+     * so picking a density here and pinching the grid are two ways of setting the same thing.
+     */
+    private void setupGridDensityPreference() {
+        if (!(findPreference("grid_density") instanceof ListPreference densityPref)) {
+            return;
+        }
+
+        densityPref.setValue(String.valueOf(Math.round(preferences.getGridColumns())));
+
+        densityPref.setOnPreferenceChangeListener((preference, newValue) -> {
+            try {
+                preferences.setGridColumns(Float.parseFloat(newValue.toString()));
+            } catch (NumberFormatException e) {
+                Log_OC.w(TAG, "Ignoring unusable grid density value: " + newValue);
+                return false;
+            }
+            return true;
+        });
     }
 
     private void updateThemePreferenceSummary(String themeValue) {

app/src/main/java/com/owncloud/android/ui/fragment/ExtendedListFragment.kt

@@ -418,6 +418,21 @@ open class ExtendedListFragment :
         scrollToPosition(referencePosition)
     }
 
+    @SuppressLint("NotifyDataSetChanged")
+    override fun onResume() {
+        super.onResume()
+
+        // The density may have been changed in the settings while this list was in the
+        // background, and the stored value is only read when the view is created.
+        val stored = preferences.getGridColumns()
+        if (stored != mScale) {
+            mScale = stored
+            // The layout manager reads the target column width again on its next layout.
+            recyclerView?.requestLayout()
+            recyclerView?.adapter?.notifyDataSetChanged()
+        }
+    }
+
     override fun onSaveInstanceState(savedInstanceState: Bundle) {
         super.onSaveInstanceState(savedInstanceState)
         Log_OC.d(TAG, "onSaveInstanceState()")

app/src/main/res/values/strings.xml

@@ -1549,4 +1549,15 @@
     <string name="governance_permission_denied">You do not have permission to change this label</string>
     <string name="file_info_governance_section_title">Governance</string>
     <string name="file_info_image_details_section_title">Image details</string>
+    <string name="prefs_grid_density_title">Grid density</string>
+    <string-array name="prefs_grid_density_entries">
+        <item>Spacious</item>
+        <item>Default</item>
+        <item>Compact</item>
+    </string-array>
+    <string-array name="prefs_grid_density_values" translatable="false">
+        <item>2</item>
+        <item>3</item>
+        <item>4</item>
+    </string-array>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -48,6 +48,12 @@
             android:defaultValue="true"
             android:title="@string/sort_favorites_first"
             android:key="sort_favorites_first" />
+        <ListPreference
+            android:title="@string/prefs_grid_density_title"
+            android:key="grid_density"
+            android:entries="@array/prefs_grid_density_entries"
+            android:entryValues="@array/prefs_grid_density_values"
+            android:summary="%s" />
     </PreferenceCategory>
 
 	<PreferenceCategory android:title="@string/prefs_category_details" android:key="details">