Refactor media views (#866)

* Migrate ImagePagerAdapter to kotlin

* Migrate ViewMediaFragment to kotlin

* Make images and videos share the same activity/pager

* Show descriptions above videos

* Cleanup

* Address code review feedback

* Migrate media fragments to constraint layout

app/src/main/java/com/keylesspalace/tusky/fragment/ViewVideoFragment.kt

@@ -0,0 +1,169 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+package com.keylesspalace.tusky.fragment
+
+import android.animation.Animator
+import android.animation.AnimatorListenerAdapter
+import android.annotation.SuppressLint
+import android.os.Bundle
+import android.os.Handler
+import android.os.Looper
+import android.support.v4.view.ViewCompat
+import android.text.TextUtils
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.MediaController
+
+import com.keylesspalace.tusky.R
+import com.keylesspalace.tusky.ViewMediaActivity
+import com.keylesspalace.tusky.entity.Attachment
+import com.keylesspalace.tusky.util.hide
+import com.keylesspalace.tusky.util.show
+import kotlinx.android.synthetic.main.activity_view_media.*
+import kotlinx.android.synthetic.main.fragment_view_video.*
+
+class ViewVideoFragment : ViewMediaFragment() {
+    private lateinit var toolbar: View
+    private val handler = Handler(Looper.getMainLooper())
+    private val hideToolbar = Runnable {
+        // Hoist toolbar hiding to activity so it can track state across different fragments
+        // This is explicitly stored as runnable so that we pass it to the handler later for cancellation
+        mediaActivity.onPhotoTap()
+    }
+    private lateinit var mediaActivity: ViewMediaActivity
+    private val TOOLBAR_HIDE_DELAY_MS = 3000L
+
+    private var showingDescription = false
+    private var isDescriptionVisible = false
+
+    companion object {
+        private const val TAG = "ViewVideoFragment"
+    }
+
+    override fun setUserVisibleHint(isVisibleToUser: Boolean) {
+        // Start/pause/resume video playback as fragment is shown/hidden
+        super.setUserVisibleHint(isVisibleToUser)
+        if (videoPlayer == null) {
+            return
+        }
+
+        if (isVisibleToUser) {
+            if (mediaActivity.isToolbarVisible()) {
+                handler.postDelayed(hideToolbar, TOOLBAR_HIDE_DELAY_MS)
+            }
+            videoPlayer?.start()
+        } else {
+            handler.removeCallbacks(hideToolbar)
+            videoPlayer?.pause()
+        }
+    }
+
+    @SuppressLint("ClickableViewAccessibility")
+    override fun setupMediaView(url: String) {
+        val videoView = videoPlayer
+        videoView.setVideoPath(url)
+        val controller = MediaController(mediaActivity)
+        controller.setMediaPlayer(videoView)
+        videoView.setMediaController(controller)
+        videoView.requestFocus()
+        videoView.setOnTouchListener { _, _ ->
+            mediaActivity.onPhotoTap()
+            false
+        }
+        videoView.setOnPreparedListener { mp ->
+            progressBar.hide()
+            mp.isLooping = true
+            if (arguments!!.getBoolean(ViewMediaFragment.ARG_START_POSTPONED_TRANSITION)) {
+                hideToolbarAfterDelay(TOOLBAR_HIDE_DELAY_MS)
+                videoView.start()
+            }
+        }
+
+        if (arguments!!.getBoolean(ViewMediaFragment.ARG_START_POSTPONED_TRANSITION)) {
+            mediaActivity.onBringUp()
+        }
+    }
+
+    private fun hideToolbarAfterDelay(delayMilliseconds: Long) {
+        handler.postDelayed(hideToolbar, delayMilliseconds)
+    }
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
+        toolbar = activity!!.toolbar
+        mediaActivity = activity as ViewMediaActivity
+        return inflater.inflate(R.layout.fragment_view_video, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        val arguments = this.arguments!!
+        val attachment = arguments.getParcelable<Attachment>(ViewMediaFragment.ARG_ATTACHMENT)
+        val url: String
+
+        if (attachment == null) {
+            throw IllegalArgumentException("attachment has to be set")
+        }
+        url = attachment.url
+        val description = attachment.description
+        mediaDescription.text = description
+        showingDescription = !TextUtils.isEmpty(description)
+        isDescriptionVisible = showingDescription
+
+        // Setting visibility without animations so it looks nice when you scroll media
+        //noinspection ConstantConditions
+        if (showingDescription && mediaActivity.isToolbarVisible()) {
+            mediaDescription.show()
+        } else {
+            mediaDescription.hide()
+
+        }
+
+        ViewCompat.setTransitionName(videoPlayer!!, url)
+
+        setupMediaView(url)
+
+        setupToolbarVisibilityListener()
+    }
+
+    override fun onToolbarVisibilityChange(visible: Boolean) {
+        if (videoPlayer == null || !userVisibleHint) {
+            return
+        }
+
+        isDescriptionVisible = showingDescription && visible
+        val alpha = if (isDescriptionVisible) 1.0f else 0.0f
+        mediaDescription.animate().alpha(alpha)
+                .setListener(object : AnimatorListenerAdapter() {
+                    override fun onAnimationEnd(animation: Animator) {
+                        if (isDescriptionVisible) {
+                            mediaDescription.show()
+                        } else {
+                            mediaDescription.hide()
+                        }
+                        animation.removeListener(this)
+                    }
+                })
+                .start()
+
+        if (visible) {
+            hideToolbarAfterDelay(TOOLBAR_HIDE_DELAY_MS)
+        } else {
+            handler.removeCallbacks(hideToolbar)
+        }
+    }
+}