Tweaks to Alt-sends-esc

+ Move to the Keyboard section of preferences.
+ On by default. (and now we actually honor the default.)
+ Rework preference text to make it clearer.
+ Rename string resource id names to make their role clearer.

+ Add support for setting the high bit instead of sending ESC.
   - I think there are more people who want this than the
     original composing logic.

+ Treat the Meta key the same way as the Alt key.
  - I considered having this be a separate preference, but
    there's a flaw: Some keyboards such as the popular
    Hacker's keyboard have a key labeled "Alt" that actually
    reports as "Meta" in software.

    So let's treat both Alt and Meta the same for now.

+ Make this code work on Android SDK 11+ physical keyboards

Android SDK 11+ physical keyboards are "chording" as opposed to
"toggling". Therefore we have to handle the !allowToggle case.

Also, the Meta flags can come in as a combination of
3 bits, so to mask them off we need to mask with META_ALT_MASK
rather than just META_ALT_ON.

6 files changed, 44 insertions, 10 deletions

diff --git a/libraries/emulatorview/src/jackpal/androidterm/emulatorview/EmulatorView.java b/libraries/emulatorview/src/jackpal/androidterm/emulatorview/EmulatorView.java
index fcd43e1..3005b62 100644
--- a/libraries/emulatorview/src/jackpal/androidterm/emulatorview/EmulatorView.java
+++ b/libraries/emulatorview/src/jackpal/androidterm/emulatorview/EmulatorView.java
@@ -1243,7 +1243,7 @@ public class EmulatorView extends View implements GestureDetector.OnGestureListe
     }
 
     /**
-     * Set whether to prepend the ESC keycode to the character when when pressing 
+     * Set whether to prepend the ESC keycode to the character when when pressing
      * the ALT Key.
      * @param flag
      */
diff --git a/libraries/emulatorview/src/jackpal/androidterm/emulatorview/TermKeyListener.java b/libraries/emulatorview/src/jackpal/androidterm/emulatorview/TermKeyListener.java
index 6f20c5f..304d97f 100644
--- a/libraries/emulatorview/src/jackpal/androidterm/emulatorview/TermKeyListener.java
+++ b/libraries/emulatorview/src/jackpal/androidterm/emulatorview/TermKeyListener.java
@@ -492,6 +492,8 @@ class TermKeyListener {
     private static final int META_CTRL_ON = 0x1000;
     private static final int META_SHIFT_ON = 1;
     private static final int META_CTRL_MASK = 0x7000;
+    private static final int META_META_ON   = 0x00010000;
+    private static final int META_META_MASK = 0x00070000;
 
     private String[] mKeyCodes = new String[256];
     private String[] mAppKeyCodes = new String[256];
@@ -795,6 +797,7 @@ class TermKeyListener {
         }
         int result = -1;
         boolean chordedCtrl = false;
+        boolean setHighBit = false;
         switch (keyCode) {
         case KeyEvent.KEYCODE_ALT_RIGHT:
         case KeyEvent.KEYCODE_ALT_LEFT:
@@ -833,12 +836,32 @@ class TermKeyListener {
             if (effectiveCaps) {
                 effectiveMetaState |= KeyEvent.META_SHIFT_ON;
             }
+            if (!allowToggle && (effectiveMetaState & META_ALT_ON) != 0) {
+                effectiveAlt = true;
+            }
             if (effectiveAlt) {
                 if (mAltSendsEsc) {
                     mTermSession.write(new byte[]{0x1b},0,1);
-                    effectiveMetaState &= ~KeyEvent.META_ALT_ON;
+                    effectiveMetaState &= ~KeyEvent.META_ALT_MASK;
+                } else {
+                    // Legacy behavior: Pass Alt through to allow composing characters.
+                    // effectiveMetaState |= KeyEvent.META_ALT_ON;
+                    setHighBit = true;
+                    effectiveMetaState &= ~KeyEvent.META_ALT_MASK;
+                }
+            }
+
+            // Note: The Hacker keyboard IME key labeled Alt actually sends Meta.
+
+            // Either send an ESC, or set the high bit of the character.
+
+            if ((metaState & KeyEvent.META_META_ON) != 0) {
+                if (mAltSendsEsc) {
+                    mTermSession.write(new byte[]{0x1b},0,1);
+                    effectiveMetaState &= ~KeyEvent.META_META_MASK;
                 } else {
-                    effectiveMetaState |= KeyEvent.META_ALT_ON;
+                    setHighBit = true;
+                    effectiveMetaState &= ~KeyEvent.META_META_MASK;
                 }
             }
             result = event.getUnicodeChar(effectiveMetaState);
@@ -854,6 +877,9 @@ class TermKeyListener {
         if (result >= KEYCODE_OFFSET) {
             handleKeyCode(result - KEYCODE_OFFSET, appMode);
         } else if (result >= 0) {
+            if (setHighBit) {
+                result |= 0x80;
+            }
             mTermSession.write(result);
         }
     }
diff --git a/res/values/defaults.xml b/res/values/defaults.xml
index bd2868f..1ccc579 100644
--- a/res/values/defaults.xml
+++ b/res/values/defaults.xml
@@ -8,11 +8,11 @@
    <string name="pref_fontsize_default">10</string>
    <string name="pref_color_default">1</string>
    <bool name="pref_utf8_by_default_default">false</bool>
-   <bool name="pref_alt_sends_esc_off_default">false</bool>
    <string name="pref_backaction_default">2</string>
    <string name="pref_controlkey_default">5</string>
    <string name="pref_fnkey_default">4</string>
    <string name="pref_ime_default">0</string>
+   <bool name="pref_alt_sends_esc_default">true</bool>
    <string name="pref_shell_default">/system/bin/sh -</string>
    <string name="pref_initialcommand_default"></string>
    <string name="pref_termtype_default">screen</string>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index ad08dda..8d3022d 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -144,7 +144,9 @@
   <string name="email_transcript_subject">Transcript from Android Terminal Emulator</string>
   <string name="email_transcript_chooser_title">Mail transcript using:</string>
   <string name="email_transcript_no_email_activity_found">Could not choose an email activity to send transcript.</string>
-  <string name="alt_sends_esc">Alt sends ESC</string>
-  <string name="alt_compose_char">Alt composes characters</string>
-  <string name="alt_key_behavior">Alt Key Behaviour</string>
+
+  <string name="alt_sends_esc">Alt key sends ESC</string>
+  <string name="alt_sends_esc_summary_on">Alt key sends ESC.</string>
+  <string name="alt_sends_esc_summary_off">Alt key sets high bit.</string>
+
 </resources>
diff --git a/res/xml/preferences.xml b/res/xml/preferences.xml
index d9edec7..55a348d 100644
--- a/res/xml/preferences.xml
+++ b/res/xml/preferences.xml
@@ -87,7 +87,6 @@
                 android:defaultValue="@bool/pref_utf8_by_default_default"
                 android:title="@string/title_utf8_by_default_preference"
                 android:summary="@string/summary_utf8_by_default_preference" />
-        <CheckBoxPreference android:title="@string/alt_key_behavior" android:key="alt_key_behavior" android:defaultValue="@bool/pref_alt_sends_esc_off_default" android:summaryOn="@string/alt_sends_esc" android:summaryOff="@string/alt_compose_char"/>
 
     </PreferenceCategory>
 
@@ -130,6 +129,12 @@
                 android:entryValues="@array/entryvalues_ime_preference"
                 android:dialogTitle="@string/dialog_title_ime_preference" />
 
+        <CheckBoxPreference android:title="@string/alt_sends_esc"
+                android:key="alt_sends_esc"
+                android:defaultValue="@bool/pref_alt_sends_esc_default"
+                android:summaryOn="@string/alt_sends_esc_summary_on"
+                android:summaryOff="@string/alt_sends_esc_summary_off" />
+
     </PreferenceCategory>
 
     <PreferenceCategory
diff --git a/src/jackpal/androidterm/util/TermSettings.java b/src/jackpal/androidterm/util/TermSettings.java
index fba5912..cd76ade 100644
--- a/src/jackpal/androidterm/util/TermSettings.java
+++ b/src/jackpal/androidterm/util/TermSettings.java
@@ -51,7 +51,7 @@ public class TermSettings {
     private String mPrependPath = null;
     private String mAppendPath = null;
 
-	private boolean mAltSendsEsc;
+    private boolean mAltSendsEsc;
 
     private static final String STATUSBAR_KEY = "statusbar";
     private static final String ACTIONBAR_KEY = "actionbar";
@@ -71,7 +71,7 @@ public class TermSettings {
     private static final String VERIFYPATH_KEY = "verify_path";
     private static final String PATHEXTENSIONS_KEY = "do_path_extensions";
     private static final String PATHPREPEND_KEY = "allow_prepend_path";
-    private static final String ALT_SENDS_ESC = "alt_key_behavior";
+    private static final String ALT_SENDS_ESC = "alt_sends_esc";
 
     public static final int WHITE = 0xffffffff;
     public static final int BLACK = 0xff000000;
@@ -156,6 +156,7 @@ public class TermSettings {
         mVerifyPath = res.getBoolean(R.bool.pref_verify_path_default);
         mDoPathExtensions = res.getBoolean(R.bool.pref_do_path_extensions_default);
         mAllowPathPrepend = res.getBoolean(R.bool.pref_allow_prepend_path_default);
+        mAltSendsEsc = res.getBoolean(R.bool.pref_alt_sends_esc_default);
     }
 
     public void readPrefs(SharedPreferences prefs) {