From 45af47c2fe69dc77e6d1ff05b56517754da700bc Mon Sep 17 00:00:00 2001
From: Candice Lo <chihtinglo@google.com>
Date: Tue, 28 Mar 2023 10:38:16 +0000
Subject: [PATCH] Enable text preview in dialog when dragging through seekbar

We use the heading of font scaling dialog to provide font size preview
when users are dragging through the seekbar and before they release
their fingers from the seekbar.

Bug: 274395502
Test: Manually - attach viideos to the bug
Test: atest FontScalingDialogTest
Change-Id: I3290d8c3560fea86453674bfb1f935ba6f709609
---
 packages/SystemUI/res/values/dimens.xml       |  3 +++
 packages/SystemUI/res/values/styles.xml       |  2 +-
 .../fontscaling/FontScalingDialog.kt          | 22 ++++++++++++++--
 .../fontscaling/FontScalingDialogTest.kt      | 25 +++++++++++++++++++
 4 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/packages/SystemUI/res/values/dimens.xml b/packages/SystemUI/res/values/dimens.xml
index 0c0defadd8b0b..7fb978aa1631d 100644
--- a/packages/SystemUI/res/values/dimens.xml
+++ b/packages/SystemUI/res/values/dimens.xml
@@ -1553,6 +1553,9 @@
     <dimen name="status_bar_user_chip_end_margin">12dp</dimen>
     <dimen name="status_bar_user_chip_text_size">12sp</dimen>
 
+    <!-- System UI Dialog -->
+    <dimen name="dialog_title_text_size">24sp</dimen>
+
     <!-- Internet panel related dimensions -->
     <dimen name="internet_dialog_list_max_height">662dp</dimen>
     <!-- The height of the WiFi network in Internet panel. -->
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index a3655c31fde9a..8a86fd560655a 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -1041,7 +1041,7 @@
 
     <style name="TextAppearance.Dialog.Title" parent="@android:style/TextAppearance.DeviceDefault.Large">
         <item name="android:textColor">?android:attr/textColorPrimary</item>
-        <item name="android:textSize">24sp</item>
+        <item name="android:textSize">@dimen/dialog_title_text_size</item>
         <item name="android:fontFamily">@*android:string/config_headlineFontFamily</item>
         <item name="android:lineHeight">32sp</item>
         <item name="android:gravity">center</item>
diff --git a/packages/SystemUI/src/com/android/systemui/accessibility/fontscaling/FontScalingDialog.kt b/packages/SystemUI/src/com/android/systemui/accessibility/fontscaling/FontScalingDialog.kt
index 1cdd5801b57dc..c9579d5e13567 100644
--- a/packages/SystemUI/src/com/android/systemui/accessibility/fontscaling/FontScalingDialog.kt
+++ b/packages/SystemUI/src/com/android/systemui/accessibility/fontscaling/FontScalingDialog.kt
@@ -21,6 +21,7 @@ import android.content.pm.ActivityInfo
 import android.content.res.Configuration
 import android.os.Bundle
 import android.provider.Settings
+import android.util.TypedValue
 import android.view.LayoutInflater
 import android.widget.Button
 import android.widget.SeekBar
@@ -49,8 +50,7 @@ class FontScalingDialog(
     private lateinit var seekBarWithIconButtonsView: SeekBarWithIconButtonsView
     private var lastProgress: Int = -1
 
-    private val configuration: Configuration =
-        Configuration(context.getResources().getConfiguration())
+    private val configuration: Configuration = Configuration(context.resources.configuration)
 
     override fun onCreate(savedInstanceState: Bundle?) {
         setTitle(R.string.font_scaling_dialog_title)
@@ -90,6 +90,10 @@ class FontScalingDialog(
                     if (!isTrackingTouch) {
                         // The seekbar progress is changed by icon buttons
                         changeFontSize(progress)
+                    } else {
+                        // Provide preview configuration for text instead of changing the system
+                        // font scale before users release their finger from the seekbar.
+                        createTextPreview(progress)
                     }
                 }
 
@@ -163,6 +167,20 @@ class FontScalingDialog(
         }
     }
 
+    /** Provides font size preview for text before putting the final settings to the system. */
+    fun createTextPreview(index: Int) {
+        val previewConfig = Configuration(configuration)
+        previewConfig.fontScale = strEntryValues[index].toFloat()
+
+        val previewConfigContext = context.createConfigurationContext(previewConfig)
+        previewConfigContext.theme.setTo(context.theme)
+
+        title.setTextSize(
+            TypedValue.COMPLEX_UNIT_PX,
+            previewConfigContext.resources.getDimension(R.dimen.dialog_title_text_size)
+        )
+    }
+
     companion object {
         private const val ON = "1"
         private const val OFF = "0"
diff --git a/packages/SystemUI/tests/src/com/android/systemui/accessibility/fontscaling/FontScalingDialogTest.kt b/packages/SystemUI/tests/src/com/android/systemui/accessibility/fontscaling/FontScalingDialogTest.kt
index a6dcd24371d56..353a7c370ab63 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/accessibility/fontscaling/FontScalingDialogTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/accessibility/fontscaling/FontScalingDialogTest.kt
@@ -185,4 +185,29 @@ class FontScalingDialogTest : SysuiTestCase() {
 
         fontScalingDialog.dismiss()
     }
+
+    @Test
+    fun dragSeekBar_createTextPreview() {
+        val slider: SeekBarWithIconButtonsView = spy(SeekBarWithIconButtonsView(mContext))
+        whenever(
+                fontScalingDialog.findViewById<SeekBarWithIconButtonsView>(R.id.font_scaling_slider)
+            )
+            .thenReturn(slider)
+        fontScalingDialog.show()
+        verify(slider).setOnSeekBarChangeListener(capture(seekBarChangeCaptor))
+        val seekBar: SeekBar = slider.findViewById(R.id.seekbar)!!
+
+        // Default seekbar progress for font size is 1, simulate dragging to 0 without
+        // releasing the finger
+        seekBarChangeCaptor.value.onStartTrackingTouch(seekBar)
+        seekBarChangeCaptor.value.onProgressChanged(
+            seekBar,
+            /* progress= */ 0,
+            /* fromUser= */ false
+        )
+        backgroundExecutor.runAllReady()
+
+        verify(fontScalingDialog).createTextPreview(/* index= */ 0)
+        fontScalingDialog.dismiss()
+    }
 }