Add option for keyboard height percent base

- resources.displayMetrics.heightPixels is unstable on some devices
- maybe we should change the semantics of "height percent" to physical screen size

app/src/main/java/org/fcitx/fcitx5/android/data/prefs/AppPrefs.kt

@@ -16,6 +16,7 @@ import org.fcitx.fcitx5.android.input.candidates.expanded.ExpandedCandidateStyle
 import org.fcitx.fcitx5.android.input.candidates.floating.FloatingCandidatesMode
 import org.fcitx.fcitx5.android.input.candidates.floating.FloatingCandidatesOrientation
 import org.fcitx.fcitx5.android.input.candidates.horizontal.HorizontalCandidateMode
+import org.fcitx.fcitx5.android.input.keyboard.KeyboardHeightPercentBase
 import org.fcitx.fcitx5.android.input.keyboard.LangSwitchBehavior
 import org.fcitx.fcitx5.android.input.keyboard.SpaceLongPressBehavior
 import org.fcitx.fcitx5.android.input.keyboard.SwipeSymbolDirection
@@ -50,6 +51,11 @@ class AppPrefs(private val sharedPreferences: SharedPreferences) {
         val ignoreSystemWindowInsets = switch(
             R.string.ignore_system_window_insets, "ignore_system_window_insets", false
         )
+        val keyboardHeightPercentBase = enumList(
+            R.string.keyboard_height_percent_base,
+            "keyboard_height_percent_base",
+            KeyboardHeightPercentBase.DisplayMetrics
+        )
     }
 
     inner class Keyboard : ManagedPreferenceCategory(R.string.virtual_keyboard, sharedPreferences) {

app/src/main/java/org/fcitx/fcitx5/android/input/InputView.kt

@@ -7,6 +7,7 @@ package org.fcitx.fcitx5.android.input
 
 import android.annotation.SuppressLint
 import android.content.res.Configuration
+import android.graphics.Point
 import android.os.Build
 import android.view.View
 import android.view.WindowInsets
@@ -31,6 +32,8 @@ import org.fcitx.fcitx5.android.input.broadcast.PunctuationComponent
 import org.fcitx.fcitx5.android.input.broadcast.ReturnKeyDrawableComponent
 import org.fcitx.fcitx5.android.input.candidates.horizontal.HorizontalCandidateComponent
 import org.fcitx.fcitx5.android.input.keyboard.CommonKeyActionListener
+import org.fcitx.fcitx5.android.input.keyboard.KeyboardHeightPercentBase.DisplayMetrics
+import org.fcitx.fcitx5.android.input.keyboard.KeyboardHeightPercentBase.RealSize
 import org.fcitx.fcitx5.android.input.keyboard.KeyboardWindow
 import org.fcitx.fcitx5.android.input.picker.emojiPicker
 import org.fcitx.fcitx5.android.input.picker.emoticonPicker
@@ -39,6 +42,7 @@ import org.fcitx.fcitx5.android.input.popup.PopupComponent
 import org.fcitx.fcitx5.android.input.preedit.PreeditComponent
 import org.fcitx.fcitx5.android.input.wm.InputWindowManager
 import org.fcitx.fcitx5.android.utils.unset
+import org.fcitx.fcitx5.android.utils.windowManager
 import org.mechdancer.dependency.DynamicScope
 import org.mechdancer.dependency.manager.wrapToUniqueComponent
 import org.mechdancer.dependency.plusAssign
@@ -61,6 +65,7 @@ import splitties.views.dsl.core.matchParent
 import splitties.views.dsl.core.view
 import splitties.views.dsl.core.wrapContent
 import splitties.views.imageDrawable
+import timber.log.Timber
 
 @SuppressLint("ViewConstructor")
 class InputView(
@@ -136,6 +141,9 @@ class InputView(
     private val keyboardBottomPadding = keyboardPrefs.keyboardBottomPadding
     private val keyboardBottomPaddingLandscape = keyboardPrefs.keyboardBottomPaddingLandscape
 
+    private val advancedPrefs = AppPrefs.getInstance().advanced
+    private val keyboardHeightPercentBase = advancedPrefs.keyboardHeightPercentBase
+
     private val keyboardSizePrefs = listOf(
         keyboardHeightPercent,
         keyboardHeightPercentLandscape,
@@ -143,15 +151,29 @@ class InputView(
         keyboardSidePaddingLandscape,
         keyboardBottomPadding,
         keyboardBottomPaddingLandscape,
+        keyboardHeightPercentBase,
     )
 
     private val keyboardHeightPx: Int
         get() {
+            val baseType = keyboardHeightPercentBase.getValue()
+            val base = when (baseType) {
+                DisplayMetrics -> resources.displayMetrics.heightPixels
+                RealSize -> Point().also {
+                    @Suppress("DEPRECATION")
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+                        context.display
+                    } else {
+                        context.windowManager.defaultDisplay
+                    }.getRealSize(it)
+                }.y
+            }
             val percent = when (resources.configuration.orientation) {
                 Configuration.ORIENTATION_LANDSCAPE -> keyboardHeightPercentLandscape
                 else -> keyboardHeightPercent
             }.getValue()
-            return resources.displayMetrics.heightPixels * percent / 100
+            Timber.d("keyboardHeightPx get(): baseType=${baseType}, base=${base}, percent=${percent}")
+            return base * percent / 100
         }
 
     private val keyboardSidePaddingPx: Int
@@ -255,6 +277,7 @@ class InputView(
         })
 
         keyboardPrefs.registerOnChangeListener(onKeyboardSizeChangeListener)
+        advancedPrefs.registerOnChangeListener(onKeyboardSizeChangeListener)
     }
 
     private fun updateKeyboardSize() {
@@ -360,6 +383,7 @@ class InputView(
     }
 
     override fun onDetachedFromWindow() {
+        advancedPrefs.unregisterOnChangeListener(onKeyboardSizeChangeListener)
         keyboardPrefs.unregisterOnChangeListener(onKeyboardSizeChangeListener)
         // clear DynamicScope, implies that InputView should not be attached again after detached.
         scope.clear()

app/src/main/java/org/fcitx/fcitx5/android/input/keyboard/KeyboardHeightPercentBase.kt

@@ -0,0 +1,14 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * SPDX-FileCopyrightText: Copyright 2026 Fcitx5 for Android Contributors
+ */
+
+package org.fcitx.fcitx5.android.input.keyboard
+
+import org.fcitx.fcitx5.android.R
+import org.fcitx.fcitx5.android.data.prefs.ManagedPreferenceEnum
+
+enum class KeyboardHeightPercentBase(override val stringRes: Int) : ManagedPreferenceEnum {
+    DisplayMetrics(R.string.display_metrics),
+    RealSize(R.string.real_size)
+}

app/src/main/res/values/strings.xml

@@ -318,4 +318,7 @@
     <string name="key_border_stroke">Enable stroke for key border</string>
     <string name="preferred_voice_input">Preferred voice input</string>
     <string name="edit_text_playground">EditText Playground</string>
+    <string name="keyboard_height_percent_base">Keyboard height percent base</string>
+    <string name="display_metrics">Display metrics (Resources.getDisplayMetrics)</string>
+    <string name="real_size">Real size (Display.getRealSize)</string>
 </resources>