allow controlling the brightness with sliding too

app/src/main/kotlin/com/simplemobiletools/gallery/fragments/VideoFragment.kt

@@ -7,6 +7,7 @@ import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.os.Handler
+import android.provider.Settings
 import android.util.DisplayMetrics
 import android.util.Log
 import android.view.*
@@ -51,6 +52,8 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
     private var mTouchDownY = 0f
     private var mTouchDownTime = 0L
     private var mTouchDownVolume = 0
+    private var mTouchDownBrightness = -1
+    private var mTempBrightness = 0
     private var mLastTouchY = 0f
 
     private var mSlideInfoText = ""
@@ -100,6 +103,11 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
             true
         }
 
+        mView.video_brightness_controller.setOnTouchListener { v, event ->
+            handleBrightnessTouched(event)
+            true
+        }
+
         initTimeHolder()
     }
 
@@ -164,8 +172,48 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
         }
     }
 
+    private fun handleBrightnessTouched(event: MotionEvent) {
+        when (event.action) {
+            MotionEvent.ACTION_DOWN -> {
+                mTouchDownX = event.x
+                mTouchDownY = event.y
+                mLastTouchY = event.y
+                mTouchDownTime = System.currentTimeMillis()
+                mSlideInfoText = "${getString(R.string.brightness)}:\n"
+                if (mTouchDownBrightness == -1)
+                    mTouchDownBrightness = getCurrentBrightness()
+            }
+            MotionEvent.ACTION_MOVE -> {
+                val diffX = mTouchDownX - event.x
+                val diffY = mTouchDownY - event.y
+
+                if (Math.abs(diffY) > Math.abs(diffX)) {
+                    var percent = ((diffY / ViewPagerActivity.screenHeight) * 100).toInt() * 3
+                    percent = Math.min(100, Math.max(-100, percent))
+
+                    if ((percent == 100 && event.y > mLastTouchY) || (percent == -100 && event.y < mLastTouchY)) {
+                        mTouchDownY = event.y
+                        mTouchDownBrightness = mTempBrightness
+                    }
+
+                    brightnessPercentChanged(percent)
+                }
+                mLastTouchY = event.y
+            }
+            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
+                if (System.currentTimeMillis() - mTouchDownTime < CLICK_MAX_DURATION) {
+                    mView.video_holder.performClick()
+                }
+                mTouchDownBrightness = mTempBrightness
+            }
+        }
+        mView.video_holder
+    }
+
     private fun getCurrentVolume() = context.audioManager.getStreamVolume(AudioManager.STREAM_MUSIC)
 
+    private fun getCurrentBrightness() = Settings.System.getInt(activity.contentResolver, Settings.System.SCREEN_BRIGHTNESS)
+
     private fun volumePercentChanged(percent: Int) {
         val stream = AudioManager.STREAM_MUSIC
         val maxVolume = context.audioManager.getStreamMaxVolume(stream)
@@ -186,6 +234,28 @@ class VideoFragment : ViewPagerFragment(), SurfaceHolder.Callback, SeekBar.OnSee
         }, SLIDE_INFO_FADE_DELAY)
     }
 
+    private fun brightnessPercentChanged(percent: Int) {
+        val maxBrightness = 255f
+        var newBrightness = (mTouchDownBrightness + 2.55 * percent).toFloat()
+        newBrightness = Math.min(maxBrightness, Math.max(0f, newBrightness))
+        mTempBrightness = newBrightness.toInt()
+
+        val absolutePercent = ((newBrightness / maxBrightness) * 100).toInt()
+        mView.slide_info.apply {
+            text = "$mSlideInfoText$absolutePercent%"
+            alpha = 1f
+        }
+
+        val attributes = activity.window.attributes
+        attributes.screenBrightness = absolutePercent / 100f
+        activity.window.attributes = attributes
+
+        mSlideInfoFadeHandler.removeCallbacksAndMessages(null)
+        mSlideInfoFadeHandler.postDelayed({
+            mView.slide_info.animate().alpha(0f)
+        }, SLIDE_INFO_FADE_DELAY)
+    }
+
     private fun initTimeHolder() {
         mTimeHolder = mView.video_time_holder
         val res = resources

app/src/main/res/layout/pager_video_item.xml

@@ -19,6 +19,11 @@
         android:layout_alignParentEnd="true"
         android:layout_alignParentRight="true"/>
 
+    <RelativeLayout
+        android:id="@+id/video_brightness_controller"
+        android:layout_width="@dimen/video_side_slider_width"
+        android:layout_height="match_parent"/>
+
     <ImageView
         android:id="@+id/video_play_outline"
         android:layout_width="@dimen/play_outline_size_big"