Adds foreground and background layers

- in onKeyDown() return false when the key is not handled.

The above two changes fix the handling of Fn-key combo's on devices with
a physical keyboard, allowing the android system defined fallbacks from
`/system/usr/keychars/Generic.kcm` to be properly handled.

Fixes #731.

Original diagnosis and fix by Konehaltia.

.gitattributes

@@ -0,0 +1,3 @@
+*       text=auto
+*.bat   eol=crlf
+*.sh    eol=lf

app/build.gradle

@@ -13,8 +13,8 @@ android {
         applicationId "com.termux"
         minSdkVersion 21
         targetSdkVersion 27
-        versionCode 63
-        versionName "0.63"
+        versionCode 65
+        versionName "0.65"
     }
 
     buildTypes {

app/src/main/java/com/termux/app/ExtraKeysView.java

@@ -1,13 +1,13 @@
 package com.termux.app;
 
 import android.content.Context;
+import android.os.Build;
 import android.util.AttributeSet;
 
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.ScheduledExecutorService;
 
-import android.view.Gravity;
 import android.view.HapticFeedbackConstants;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
@@ -28,8 +28,8 @@ import com.termux.view.TerminalView;
 public final class ExtraKeysView extends GridLayout {
 
     private static final int TEXT_COLOR = 0xFFFFFFFF;
-    private static final int BUTTON_COLOR = 0xFF000000;
-    private static final int BUTTON_PRESSED_COLOR = 0xFF888888;
+    private static final int BUTTON_COLOR = 0x00000000;
+    private static final int BUTTON_PRESSED_COLOR = 0x7FFFFFFF;
 
     public ExtraKeysView(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ -269,9 +269,13 @@ public final class ExtraKeysView extends GridLayout {
                 });
 
                 LayoutParams param = new GridLayout.LayoutParams();
-                param.width = param.height = 0;
+                param.width = 0;
+                if(Build.VERSION.SDK_INT == Build.VERSION_CODES.LOLLIPOP){  //special handle api 21
+                    param.height = (int)(37.5 * getResources().getDisplayMetrics().density + 0.5); // 37.5 equal to R.id.viewpager layout_heihgt / rows in DP
+                }else{
+                    param.height = 0;
+                }
                 param.setMargins(0, 0, 0, 0);
-                param.setGravity(Gravity.LEFT);
                 param.columnSpec = GridLayout.spec(col, GridLayout.FILL, 1.f);
                 param.rowSpec = GridLayout.spec(row, GridLayout.FILL, 1.f);
                 button.setLayoutParams(param);

app/src/main/java/com/termux/app/TermuxInstaller.java

@@ -209,18 +209,18 @@ final class TermuxInstaller {
             Arrays.toString(Build.SUPPORTED_ABIS));
     }
 
-    /** Delete a folder and all its content or throw. */
+    /** Delete a folder and all its content or throw. Don't follow symlinks. */
     static void deleteFolder(File fileOrDirectory) throws IOException {
-        File[] children = fileOrDirectory.listFiles();
-        if (children != null) {
-            for (File child : children) {
-                if (child.getCanonicalFile().equals(child.getAbsoluteFile())) {
+        if (fileOrDirectory.getCanonicalPath().equals(fileOrDirectory.getAbsolutePath()) && fileOrDirectory.isDirectory()) {
+            File[] children = fileOrDirectory.listFiles();
+
+            if (children != null) {
+                for (File child : children) {
                     deleteFolder(child);
-                } else {
-                    child.delete();
                 }
             }
         }
+
         if (!fileOrDirectory.delete()) {
             throw new RuntimeException("Unable to delete " + (fileOrDirectory.isDirectory() ? "directory " : "file ") + fileOrDirectory.getAbsolutePath());
         }

app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/ic_background"/>
+    <foreground android:drawable="@mipmap/ic_foreground"/>
+</adaptive-icon>

terminal-view/src/main/java/com/termux/view/TerminalView.java

@@ -15,6 +15,7 @@ import android.text.InputType;
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.view.accessibility.AccessibilityManager;
 import android.view.ActionMode;
 import android.view.HapticFeedbackConstants;
 import android.view.InputDevice;
@@ -75,6 +76,8 @@ public final class TerminalView extends View {
     /** If non-zero, this is the last unicode code point received if that was a combining character. */
     int mCombiningAccent;
 
+    private boolean mAccessibilityEnabled;
+
     public TerminalView(Context context, AttributeSet attributes) { // NO_UCD (unused code)
         super(context, attributes);
         mGestureRecognizer = new GestureAndScaleRecognizer(context, new GestureAndScaleRecognizer.Listener() {
@@ -197,6 +200,8 @@ public final class TerminalView extends View {
             }
         });
         mScroller = new Scroller(context);
+        AccessibilityManager am = (AccessibilityManager) context.getSystemService(context.ACCESSIBILITY_SERVICE);
+        mAccessibilityEnabled = am.isEnabled();
     }
 
     /**
@@ -384,6 +389,7 @@ public final class TerminalView extends View {
         mEmulator.clearScrollCounter();
 
         invalidate();
+        if (mAccessibilityEnabled) setContentDescription(getText());
     }
 
     /**
@@ -594,7 +600,7 @@ public final class TerminalView extends View {
         if (controlDownFromEvent) keyMod |= KeyHandler.KEYMOD_CTRL;
         if (event.isAltPressed()) keyMod |= KeyHandler.KEYMOD_ALT;
         if (event.isShiftPressed()) keyMod |= KeyHandler.KEYMOD_SHIFT;
-        if (handleKeyCode(keyCode, keyMod)) {
+        if (!event.isFunctionPressed() && handleKeyCode(keyCode, keyMod)) {
             if (LOG_KEY_EVENTS) Log.i(EmulatorDebug.LOG_TAG, "handleKeyCode() took key event");
             return true;
         }
@@ -613,7 +619,7 @@ public final class TerminalView extends View {
         if (LOG_KEY_EVENTS)
             Log.i(EmulatorDebug.LOG_TAG, "KeyEvent#getUnicodeChar(" + effectiveMetaState + ") returned: " + result);
         if (result == 0) {
-            return true;
+            return false;
         }
 
         int oldCombiningAccent = mCombiningAccent;
@@ -915,4 +921,8 @@ public final class TerminalView extends View {
         return mTermSession;
     }
 
+    private CharSequence getText() {
+        return mEmulator.getScreen().getSelectedText(0, mTopRow, mEmulator.mColumns, mTopRow +mEmulator.mRows);
+    }
+
 }