fix(keyboard): preserve ascii_mode across keyboard switches (#1979)

When switching between keyboard layouts, ascii_mode is unconditionally
reset to the keyboard's default, discarding the user's current input
mode.

This happends due to TextKeyboard always defaults reset_ascii_mode to
true, overriding the global theme setting, and lastAsciiMode is never
saved when leaving a keyboard.

Fix this by making TextKeyboard.resetAsciiMode nullable so that unset
values fall through to the global theme settings in Keyboard, saving the
current ascii_mode before switching away. Each keyboard's resetAsciiMode
now falls back to the global setting and determines whether to reset or
restore the previous mode.

v1->v2:
 - Fix regression in KeyboardWindow::attachKeyboard()

Signed-off-by: Xavier Hsinyuan <me@lstlx.com>

app/src/main/java/com/osfans/trime/data/theme/model/TextKeyboard.kt

@@ -32,7 +32,7 @@ data class TextKeyboard(
     val keyBorder: Int,
     val columns: Int,
     val asciiMode: Boolean,
-    val resetAsciiMode: Boolean,
+    val resetAsciiMode: Boolean?,
     val labelTransform: LabelTransform,
     val lock: Boolean,
     val asciiKeyboard: String,
@@ -140,7 +140,7 @@ data class TextKeyboard(
             keyBorder = node["key_border"]?.int ?: -1,
             columns = node["columns"]?.int ?: 30,
             asciiMode = (node["ascii_mode"]?.int ?: 1) == 1,
-            resetAsciiMode = node["reset_ascii_mode"]?.boolean ?: true,
+            resetAsciiMode = node["reset_ascii_mode"]?.boolean,
             labelTransform = node["label_transform"]?.enum<LabelTransform>() ?: LabelTransform.NONE,
             lock = node["lock"]?.boolean ?: false,
             asciiKeyboard = node["ascii_keyboard"]?.string ?: "",

app/src/main/java/com/osfans/trime/ime/keyboard/Keyboard.kt

@@ -122,7 +122,7 @@ class Keyboard(
 
     /** Keyboard default ascii mode  */
     val asciiMode = selfConfig?.asciiMode ?: false
-    val resetAsciiMode = selfConfig?.resetAsciiMode ?: true
+    val resetAsciiMode = selfConfig?.resetAsciiMode ?: theme.generalStyle.resetASCIIMode
     var lastAsciiMode: Boolean = asciiMode
 
     val landscapeKeyboard: String? = selfConfig?.landscapeKeyboard

app/src/main/java/com/osfans/trime/ime/keyboard/KeyboardWindow.kt

@@ -105,6 +105,13 @@ class KeyboardWindow :
     }
 
     private fun attachKeyboard(target: String) {
+        currentKeyboard?.let {
+            val mode = rime.run { statusCached }.isAsciiMode
+
+            Timber.d("Leaving $currentKeyboardId with ascii_mode $mode, switching to $target")
+            it.lastAsciiMode = mode
+        }
+
         currentKeyboardId = target
         lastKeyboardId = target