fix(ui): support foldables and large screens instead of running in compat mode

app/src/main/java/com/wytehat/btlogger/DeviceManagerActivity.java

@@ -239,6 +239,7 @@ public class DeviceManagerActivity extends Activity {
         root.addView(pairedList, new LinearLayout.LayoutParams(-1, 0, 1));
         pairedHeader.setVisibility(View.GONE); pairedList.setVisibility(View.GONE);
         setContentView(root);
+        LargeScreenLayout.constrain(this);
 
         IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
         filter.addAction(BluetoothDevice.ACTION_FOUND);

app/src/main/java/com/wytehat/btlogger/LargeScreenLayout.java

@@ -0,0 +1,72 @@
+package com.wytehat.btlogger;
+
+import android.app.Activity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+
+/**
+ * Keeps the phone-sized UI readable on tablets and unfolded foldables.
+ *
+ * The screens are laid out for a ~360dp phone. Stretched across a 670dp+
+ * inner display every row spans the full width, which leaves controls
+ * marooned at opposite edges. Centering the content in a phone-width column
+ * keeps the proportions the layouts were designed for.
+ */
+final class LargeScreenLayout {
+
+    /** Below this the layout is already phone-shaped; leave it alone. */
+    private static final int WIDE_THRESHOLD_DP = 640;
+
+    /** Column width used once the screen is wider than the threshold. */
+    private static final int CONTENT_WIDTH_DP = 600;
+
+    private LargeScreenLayout() {
+    }
+
+    /**
+     * Call after setContentView. No-op on phones and on folded screens.
+     */
+    static void constrain(Activity activity) {
+
+        float density =
+            activity.getResources().getDisplayMetrics().density;
+
+        int widthDp = (int)
+            (activity.getResources().getDisplayMetrics().widthPixels / density);
+
+        if (widthDp < WIDE_THRESHOLD_DP) {
+            return;
+        }
+
+        View content =
+            activity.findViewById(android.R.id.content);
+
+        if (!(content instanceof ViewGroup)) {
+            return;
+        }
+
+        ViewGroup holder = (ViewGroup) content;
+
+        if (holder.getChildCount() == 0) {
+            return;
+        }
+
+        View root = holder.getChildAt(0);
+
+        ViewGroup.LayoutParams existing =
+            root.getLayoutParams();
+
+        if (!(existing instanceof FrameLayout.LayoutParams)) {
+            return;
+        }
+
+        FrameLayout.LayoutParams params =
+            (FrameLayout.LayoutParams) existing;
+
+        params.width = (int) (CONTENT_WIDTH_DP * density + 0.5f);
+        params.gravity = android.view.Gravity.CENTER_HORIZONTAL;
+
+        root.setLayoutParams(params);
+    }
+}

app/src/main/java/com/wytehat/btlogger/LiveRangeFinderActivity.java

@@ -169,6 +169,7 @@ public class LiveRangeFinderActivity extends Activity implements LocationListene
         root.addView(map, new LinearLayout.LayoutParams(
             LinearLayout.LayoutParams.MATCH_PARENT, 0, 1));
         setContentView(root);
+        LargeScreenLayout.constrain(this);
 
         startButton.setOnClickListener(new View.OnClickListener() {
             public void onClick(View view) { startSearch(); }

app/src/main/java/com/wytehat/btlogger/MainActivity.java

@@ -32,6 +32,7 @@ public class MainActivity extends Activity implements ItemActionListener {
     protected void onCreate(Bundle state) {
         super.onCreate(state);
         setContentView(R.layout.main);
+        LargeScreenLayout.constrain(this);
         LinearLayout nav = (LinearLayout) findViewById(R.id.navigation_container);
         nav.addView(NavigationHelper.createBar(this, 0, "My Tracked Items"));
         db = new TrackerDatabase(this);