From 14dabb6f519275a800f1fbf13620f420555b0d0c Mon Sep 17 00:00:00 2001
From: Jules Aguillon <jules@j3s.fr>
Date: Tue, 22 Feb 2022 19:32:16 +0100
Subject: [PATCH] Send key events for the modifiers

Before sending a key event while modifiers are active, send events for
the modifier keys.

Some applications don't look at the "metaState" flags but instead keep
track of the up and down events for the modifiers.

For example, the basic text views that are in every applications
correctly handle the "metaState" flags except for one binding:
Selecting text with the arrows while pressing shift.
---
 srcs/juloo.keyboard2/KeyEventHandler.java | 53 ++++++++++++++++-------
 srcs/juloo.keyboard2/Keyboard2.java       |  6 +--
 2 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/srcs/juloo.keyboard2/KeyEventHandler.java b/srcs/juloo.keyboard2/KeyEventHandler.java
index dad6642..86cfc8c 100644
--- a/srcs/juloo.keyboard2/KeyEventHandler.java
+++ b/srcs/juloo.keyboard2/KeyEventHandler.java
@@ -25,11 +25,11 @@ class KeyEventHandler implements Config.IKeyEventHandler
     case KeyValue.EVENT_ACTION: _recv.performAction(); return;
     default:
       if ((flags & (KeyValue.FLAG_CTRL | KeyValue.FLAG_ALT | KeyValue.FLAG_META)) != 0)
-        handleMetaKeyUp(key, flags);
+        handleKeyUpWithModifier(key, flags);
       else if (key.char_ != KeyValue.CHAR_NONE)
         _recv.commitChar(key.char_);
       else if (key.eventCode != KeyValue.EVENT_NONE)
-        handleMetaKeyUp(key, flags);
+        handleKeyUpWithModifier(key, flags);
       else
         _recv.commitText(key.symbol);
     }
@@ -45,22 +45,43 @@ class KeyEventHandler implements Config.IKeyEventHandler
   //  getCurrentInputConnection().deleteSurroundingText(before, after);
   // }
 
-  private void handleMetaKeyUp(KeyValue key, int flags)
+  private int sendMetaKey(int eventCode, int metaFlags, int metaState, boolean down)
   {
-    int meta = 0;
-    if (key.eventCode == KeyValue.EVENT_NONE)
-      return ;
-    if ((flags & KeyValue.FLAG_CTRL) != 0)
-      meta |= KeyEvent.META_CTRL_LEFT_ON | KeyEvent.META_CTRL_ON;
-    if ((flags & KeyValue.FLAG_ALT) != 0)
-      meta |= KeyEvent.META_ALT_LEFT_ON | KeyEvent.META_ALT_ON;
-    if ((flags & KeyValue.FLAG_SHIFT) != 0)
-      meta |= KeyEvent.META_SHIFT_LEFT_ON | KeyEvent.META_SHIFT_ON;
-    if ((flags & KeyValue.FLAG_META) != 0)
-      meta |= KeyEvent.META_META_LEFT_ON | KeyEvent.META_META_ON;
-    _recv.sendKeyEvent(key.eventCode, meta);
+    int action;
+    int updatedMetaState;
+    if (down) { action = KeyEvent.ACTION_DOWN; updatedMetaState = metaState | metaFlags; }
+    else { action = KeyEvent.ACTION_UP; updatedMetaState = metaState & ~metaFlags; }
+    _recv.sendKeyEvent(action, eventCode, metaState);
+    return updatedMetaState;
   }
 
+  /* Send key events corresponding to pressed modifier keys. */
+  private int sendMetaKeys(int flags, int metaState, boolean down)
+  {
+		if ((flags & KeyValue.FLAG_CTRL) != 0)
+      metaState = sendMetaKey(KeyEvent.KEYCODE_CTRL_LEFT, KeyEvent.META_CTRL_LEFT_ON | KeyEvent.META_CTRL_ON, metaState, down);
+		if ((flags & KeyValue.FLAG_ALT) != 0)
+      metaState = sendMetaKey(KeyEvent.KEYCODE_ALT_LEFT, KeyEvent.META_ALT_LEFT_ON | KeyEvent.META_ALT_ON, metaState, down);
+		if ((flags & KeyValue.FLAG_SHIFT) != 0)
+      metaState = sendMetaKey(KeyEvent.KEYCODE_SHIFT_LEFT, KeyEvent.META_SHIFT_LEFT_ON | KeyEvent.META_SHIFT_ON, metaState, down);
+    if ((flags & KeyValue.FLAG_META) != 0)
+      metaState = sendMetaKey(KeyEvent.KEYCODE_META_LEFT, KeyEvent.META_META_LEFT_ON | KeyEvent.META_META_ON, metaState, down);
+    return metaState;
+  }
+
+  /*
+   * Don't set KeyEvent.FLAG_SOFT_KEYBOARD.
+   */
+	private void handleKeyUpWithModifier(KeyValue key, int flags)
+	{
+		if (key.eventCode == KeyValue.EVENT_NONE)
+			return ;
+    int metaState = sendMetaKeys(flags, 0, true);
+		_recv.sendKeyEvent(KeyEvent.ACTION_DOWN, key.eventCode, metaState);
+    _recv.sendKeyEvent(KeyEvent.ACTION_UP, key.eventCode, metaState);
+    sendMetaKeys(flags, metaState, false);
+	}
+
   public static interface IReceiver
   {
     public void switchToNextInputMethod();
@@ -72,7 +93,7 @@ class KeyEventHandler implements Config.IKeyEventHandler
     /** 'res_id' is '-1' for the currently selected layout. */
     public void setLayout(int res_id);
 
-    public void sendKeyEvent(int eventCode, int meta);
+    public void sendKeyEvent(int eventAction, int eventCode, int meta);
 
     public void commitText(String text);
     public void commitChar(char c);
diff --git a/srcs/juloo.keyboard2/Keyboard2.java b/srcs/juloo.keyboard2/Keyboard2.java
index 0ce3af8..44b36a1 100644
--- a/srcs/juloo.keyboard2/Keyboard2.java
+++ b/srcs/juloo.keyboard2/Keyboard2.java
@@ -256,14 +256,12 @@ public class Keyboard2 extends InputMethodService
       _keyboardView.setKeyboard(getLayout(res_id));
     }
 
-    public void sendKeyEvent(int eventCode, int meta)
+    public void sendKeyEvent(int eventAction, int eventCode, int meta)
     {
       InputConnection conn = getCurrentInputConnection();
       if (conn == null)
         return;
-      KeyEvent event = new KeyEvent(1, 1, KeyEvent.ACTION_DOWN, eventCode, 0, meta);
-      conn.sendKeyEvent(event);
-      conn.sendKeyEvent(KeyEvent.changeAction(event, KeyEvent.ACTION_UP));
+      conn.sendKeyEvent(new KeyEvent(1, 1, eventAction, eventCode, 0, meta));
     }
 
     public void showKeyboardConfig()