Merge pull request #15902 from nextcloud/perf/gallery-row-holder-caching

perf: gallery row holder caching

Author: tobiasKaminsky

app/src/main/java/com/owncloud/android/ui/adapter/GalleryRowHolder.kt

@@ -10,6 +10,7 @@ package com.owncloud.android.ui.adapter
 
 import android.view.Gravity
 import android.view.View
+import android.view.ViewGroup
 import android.widget.FrameLayout
 import android.widget.ImageView
 import androidx.core.content.ContextCompat
@@ -44,32 +45,55 @@ class GalleryRowHolder(
     val context = galleryAdapter.context
 
     private lateinit var currentRow: GalleryRow
+
+    // Cached values
     private val zero by lazy { context.resources.getInteger(R.integer.zero) }
     private val smallMargin by lazy { context.resources.getInteger(R.integer.small_margin) }
     private val iconRadius by lazy { context.resources.getDimension(R.dimen.activity_icon_radius) }
     private val standardMargin by lazy { context.resources.getDimension(R.dimen.standard_margin) }
     private val checkBoxMargin by lazy { context.resources.getDimension(R.dimen.standard_quarter_padding) }
 
-    fun bind(row: GalleryRow) {
-        currentRow = row
+    private val defaultBitmap by lazy {
+        val fileDrawable = ResourcesCompat.getDrawable(context.resources, R.drawable.file_image, null)
+        val thumbnailSize = defaultThumbnailSize.toInt()
+        BitmapUtils.drawableToBitmap(fileDrawable, thumbnailSize, thumbnailSize)
+    }
 
-        // re-use existing ones
-        while (binding.rowLayout.childCount < row.files.size) {
-            val rowLayout = getRowLayout()
-            binding.rowLayout.addView(rowLayout)
+    private val checkedDrawable by lazy {
+        ContextCompat.getDrawable(context, R.drawable.ic_checkbox_marked)?.also {
+            viewThemeUtils.platform.tintDrawable(context, it, ColorRole.PRIMARY)
         }
+    }
+
+    private val uncheckedDrawable by lazy {
+        ContextCompat.getDrawable(context, R.drawable.ic_checkbox_blank_outline)
+    }
 
-        if (binding.rowLayout.childCount > row.files.size) {
-            binding.rowLayout.removeViews(row.files.size, binding.rowLayout.childCount - row.files.size)
+    private var lastFileCount = -1
+    // endregion
+
+    fun bind(row: GalleryRow) {
+        currentRow = row
+        val requiredCount = row.files.size
+
+        // Only rebuild if file count changed
+        if (lastFileCount != requiredCount) {
+            binding.rowLayout.removeAllViews()
+            repeat(requiredCount) { binding.rowLayout.addView(getRowLayout()) }
+            lastFileCount = requiredCount
         }
 
         val shrinkRatio = computeShrinkRatio(row)
 
-        for (indexedFile in row.files.withIndex()) {
-            adjustFile(indexedFile, shrinkRatio, row)
+        for (i in row.files.indices) {
+            adjustFile(i, row.files[i], shrinkRatio, row)
         }
     }
 
+    fun updateRowVisuals() {
+        bind(currentRow)
+    }
+
     private fun getRowLayout(): FrameLayout {
         val checkbox = ImageView(context).apply {
             visibility = View.GONE
@@ -89,16 +113,15 @@ class GalleryRowHolder(
             invalidate()
         }
 
-        val fileDrawable = ResourcesCompat.getDrawable(context.resources, R.drawable.file_image, null)
-        val thumbnailSize = defaultThumbnailSize.toInt()
-        val bitmap = BitmapUtils.drawableToBitmap(fileDrawable, thumbnailSize, thumbnailSize)
         val drawable = ThumbnailsCacheManager.AsyncGalleryImageDrawable(
             context.resources,
-            bitmap,
+            defaultBitmap,
             null
         )
         val rowCellImageView = ImageView(context).apply {
             setImageDrawable(drawable)
+            adjustViewBounds = true
+            scaleType = ImageView.ScaleType.FIT_XY
         }
 
         return FrameLayout(context).apply {
@@ -108,10 +131,6 @@ class GalleryRowHolder(
         }
     }
 
-    fun redraw() {
-        bind(currentRow)
-    }
-
     @SuppressWarnings("MagicNumber")
     private fun computeShrinkRatio(row: GalleryRow): Float {
         val screenWidth = DisplayUtils.convertDpToPixel(
@@ -148,20 +167,14 @@ class GalleryRowHolder(
         return (screenWidth / galleryAdapter.columns) / width
     }
 
-    private fun adjustFile(indexedFile: IndexedValue<OCFile>, shrinkRatio: Float, row: GalleryRow) {
-        val file = indexedFile.value
-        val index = indexedFile.index
-
+    private fun adjustFile(index: Int, file: OCFile, shrinkRatio: Float, row: GalleryRow) {
         val width = file.imageDimension?.width?.times(shrinkRatio)?.toInt() ?: 0
         val height = file.imageDimension?.height?.times(shrinkRatio)?.toInt() ?: 0
 
         val frameLayout = binding.rowLayout[index] as FrameLayout
-        val checkBoxImageView = frameLayout[2] as ImageView
         val shimmer = frameLayout[0] as LoaderImageView
-        val thumbnail = (frameLayout[1] as ImageView).apply {
-            adjustViewBounds = true
-            scaleType = ImageView.ScaleType.FIT_XY
-        }
+        val thumbnail = frameLayout[1] as ImageView
+        val checkBoxImageView = frameLayout[2] as ImageView
 
         val isChecked = ocFileListDelegate.isCheckedFile(file)
 
@@ -176,43 +189,59 @@ class GalleryRowHolder(
             width
         )
 
+        // Update layout params only if they differ
+        val thumbLp = thumbnail.layoutParams
+        if (thumbLp.width != width || thumbLp.height != height) {
+            thumbnail.layoutParams = thumbLp.getFrameLayout(width, height).apply {
+                val endMargin = if (index < row.files.size - 1) smallMargin else zero
+                this.setMargins(zero, zero, endMargin, smallMargin)
+            }
+        }
+
+        val shimmerLp = shimmer.layoutParams
+        if (shimmerLp.width != width || shimmerLp.height != height) {
+            shimmer.layoutParams = shimmerLp.getFrameLayout(width, height)
+        }
+
         // Force layout update
         frameLayout.requestLayout()
+    }
 
-        val params = FrameLayout.LayoutParams(width, height)
-        val endMargin = if (index < row.files.size - 1) smallMargin else zero
-        params.setMargins(zero, zero, endMargin, smallMargin)
-
-        thumbnail.layoutParams = params
-        shimmer.layoutParams = FrameLayout.LayoutParams(params)
+    private fun ViewGroup.LayoutParams?.getFrameLayout(width: Int, height: Int): FrameLayout.LayoutParams = (
+        this as? FrameLayout.LayoutParams
+            ?: FrameLayout.LayoutParams(width, height)
+        ).apply {
+        this.width = width
+        this.height = height
     }
 
     @Suppress("MagicNumber")
     private fun adjustRowCell(imageView: ImageView, isChecked: Boolean) {
-        imageView.apply {
-            scaleX = if (isChecked) 0.8f else 1.0f
-            scaleY = scaleX
-            makeRounded(context, if (isChecked) iconRadius else 0f)
+        val scale = if (isChecked) 0.8f else 1.0f
+        val radius = if (isChecked) iconRadius else 0f
+
+        // Only update if values changed
+        if (imageView.scaleX != scale) {
+            imageView.scaleX = scale
+            imageView.scaleY = scale
         }
+
+        imageView.makeRounded(context, radius)
     }
 
     private fun adjustCheckBox(imageView: ImageView, isChecked: Boolean) {
         if (ocFileListDelegate.isMultiSelect) {
-            val checkboxDrawable = (
-                if (isChecked) {
-                    val drawable = ContextCompat.getDrawable(context, R.drawable.ic_checkbox_marked)
-                    drawable?.let {
-                        viewThemeUtils.platform.tintDrawable(context, drawable, ColorRole.PRIMARY)
-                    }
-                    drawable
-                } else {
-                    ContextCompat.getDrawable(context, R.drawable.ic_checkbox_blank_outline)
-                }
-                )?.apply {
+            val checkboxDrawable = if (isChecked) checkedDrawable else uncheckedDrawable
+
+            checkboxDrawable?.apply {
                 val margin = standardMargin.toInt()
                 setBounds(margin, margin, margin, margin)
             }
-            imageView.setImageDrawable(checkboxDrawable)
+
+            // Only set if different
+            if (imageView.drawable !== checkboxDrawable) {
+                imageView.setImageDrawable(checkboxDrawable)
+            }
         }
 
         imageView.setVisibleIf(ocFileListDelegate.isMultiSelect)

app/src/main/java/com/owncloud/android/ui/adapter/OCFileListDelegate.kt

@@ -196,8 +196,8 @@ class OCFileListDelegate(
                 }
 
                 override fun onNewGalleryImage() {
-                    Log_OC.d(tag, "setGalleryImage.redraw()")
-                    galleryRowHolder.redraw()
+                    Log_OC.d(tag, "updateRowVisuals")
+                    galleryRowHolder.updateRowVisuals()
                 }
 
                 override fun onError() {