xiaomi keyboard hack

app/src/main/java/io/github/sspanak/tt9/hacks/DeviceInfo.java

@@ -10,11 +10,17 @@ import android.view.KeyEvent;
 import androidx.annotation.NonNull;
 
 public class DeviceInfo {
-	private static Boolean isRobo = null;
-
 	public static boolean noKeyboard(Context context) {
+		// all Xiaomi phones are only touchscreen, but some of them report they have a keyboard
+		// See: https://github.com/sspanak/tt9/issues/549
+		if (DeviceInfo.isXiaomi()) {
+			return true;
+		}
+
+		Configuration configuration = context.getResources().getConfiguration();
+
 		return
-			context.getResources().getConfiguration().keyboard == Configuration.KEYBOARD_NOKEYS
+			(configuration.keyboard == Configuration.KEYBOARD_NOKEYS || configuration.hardKeyboardHidden == Configuration.HARDKEYBOARDHIDDEN_YES)
 			&& !KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_STAR)
 			&& !KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_POUND);
 	}
@@ -43,6 +49,10 @@ public class DeviceInfo {
 		return isSonim() && Build.VERSION.SDK_INT == Build.VERSION_CODES.R && noTouchScreen(context);
 	}
 
+	public static boolean isXiaomi() {
+		return Build.MANUFACTURER.equals("Xiaomi");
+	}
+
 	@NonNull
 	@Override
 	public String toString() {

app/src/main/java/io/github/sspanak/tt9/hacks/InputType.java

@@ -42,6 +42,7 @@ public class InputType extends StandardInputType {
 
 
 	public boolean isDumbPhoneDialer(Context context) {
+		// the inputType is not always TYPE_CLASS_PHONE on all devices, so we must not filter by that.
 		return field.packageName.endsWith(".dialer") && !DeviceInfo.noKeyboard(context);
 	}
 
@@ -133,8 +134,10 @@ public class InputType extends StandardInputType {
 	 * <a href="https://github.com/sspanak/tt9/issues/46">the initial GitHub issue about Qin F21 Pro+</a>
 	 * <a href="https://github.com/sspanak/tt9/pull/326">the PR about calculators</a>
 	 * <a href="https://github.com/sspanak/tt9/issues/300">Dialer not detected correctly on LG X100S</a>
-	 * [NO ISSUE] On touchscreen-only phones, in the Dialer app, we can't switch to passthrough, because
+	 * [NO ISSUE] On touchscreen-only phones, in the Dialer app, we mustn't switch to passthrough, because
 	 * they don't have a physical keyboard.
+	 * <a href="https://github.com/sspanak/tt9/issues/538">Beeps on CAT S22 Flip</a>
+	 * <a href="https://github.com/sspanak/tt9/issues/549">The UI does not appear on Xiaomi Redmi 12c</a>
 	 */
 	protected boolean isSpecialNumeric(Context context) {
 		return