feat(*): 添加几个图片相关的扩展函数

Author: AndroidCoderPeng

lite/src/main/java/com/pengxh/kt/lite/extensions/Drawable.kt

@@ -0,0 +1,39 @@
+package com.pengxh.kt.lite.extensions
+
+import android.content.Context
+import android.graphics.Bitmap
+import android.graphics.drawable.Drawable
+import android.renderscript.Allocation
+import android.renderscript.Element
+import android.renderscript.RenderScript
+import android.renderscript.ScriptIntrinsicBlur
+import androidx.core.graphics.drawable.toBitmap
+import kotlin.math.roundToInt
+
+
+private const val BITMAP_SCALE = 0.4f
+
+fun Drawable.toBlurBitmap(context: Context, radius: Float): Bitmap {
+    val bitmap = this.toBitmap()
+
+    // 计算图片缩小后的长宽
+    val width = (bitmap.width * BITMAP_SCALE).roundToInt()
+    val height = (bitmap.height * BITMAP_SCALE).roundToInt()
+
+    // 将缩小后的图片做为预渲染的图片。
+    val inputBitmap = Bitmap.createScaledBitmap(bitmap, width, height, false)
+    // 创建一张渲染后的输出图片。
+    val outputBitmap = Bitmap.createBitmap(inputBitmap)
+
+    // 创建RenderScript内核对象
+    val rs = RenderScript.create(context)
+    // 创建一个模糊效果的RenderScript的工具对象
+    val blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs))
+    val tmpIn = Allocation.createFromBitmap(rs, inputBitmap)
+    val tmpOut = Allocation.createFromBitmap(rs, outputBitmap)
+    blurScript.setRadius(radius)
+    blurScript.setInput(tmpIn)
+    blurScript.forEach(tmpOut)
+    tmpOut.copyTo(outputBitmap)
+    return outputBitmap
+}

lite/src/main/java/com/pengxh/kt/lite/extensions/ImageView.kt

@@ -0,0 +1,48 @@
+package com.pengxh.kt.lite.extensions
+
+import android.graphics.Bitmap
+import android.graphics.Color
+import android.graphics.drawable.BitmapDrawable
+import android.graphics.drawable.ColorDrawable
+import android.graphics.drawable.Drawable
+import android.graphics.drawable.TransitionDrawable
+import android.widget.ImageView
+
+
+fun ImageView.switchBackground(blurBitmap: Bitmap) {
+    var transitionDrawable: TransitionDrawable? = null
+    val lastDrawable: Drawable
+    when (this.drawable) {
+        is TransitionDrawable -> {
+            transitionDrawable = this.drawable as TransitionDrawable
+            lastDrawable = transitionDrawable.findDrawableByLayerId(
+                transitionDrawable.getId(1)
+            )
+        }
+
+        is BitmapDrawable -> {
+            lastDrawable = this.drawable
+        }
+
+        else -> {
+            lastDrawable = ColorDrawable(Color.TRANSPARENT)
+        }
+    }
+
+    if (transitionDrawable == null) {
+        transitionDrawable = TransitionDrawable(
+            arrayOf(lastDrawable, BitmapDrawable(resources, blurBitmap))
+        )
+        transitionDrawable.setId(0, 0)
+        transitionDrawable.setId(1, 1)
+        transitionDrawable.isCrossFadeEnabled = true
+        this.setImageDrawable(transitionDrawable)
+    } else {
+        transitionDrawable.setDrawableByLayerId(transitionDrawable.getId(0), lastDrawable)
+        transitionDrawable.setDrawableByLayerId(
+            transitionDrawable.getId(1),
+            BitmapDrawable(resources, blurBitmap)
+        )
+    }
+    transitionDrawable.startTransition(1000)
+}

lite/src/main/java/com/pengxh/kt/lite/utils/GalleryScaleHelper.kt

@@ -0,0 +1,83 @@
+package com.pengxh.kt.lite.utils
+
+import android.view.View
+import androidx.recyclerview.widget.LinearSnapHelper
+import androidx.recyclerview.widget.RecyclerView
+import com.pengxh.kt.lite.extensions.dp2px
+import kotlin.math.abs
+import kotlin.math.max
+
+
+class GalleryScaleHelper {
+
+    private val kTag = "GalleryScaleHelper"
+    private val snapHelper by lazy { LinearSnapHelper() }
+
+    // 卡片的padding, 卡片间的距离等于2倍的pagePadding
+    private val pagePadding = 15
+
+    // 左边卡片显示大小
+    private val leftCardShowWidth = 15
+
+    // 卡片宽度
+    private var cardWidth = 0
+    private var currentItemOffset = 0
+
+    //当前卡片的index
+    private var currentItemPos = 0
+
+    // 两边视图缩放比例
+    private val scale = 0.9f
+
+    fun attachToRecyclerView(recyclerView: RecyclerView) {
+        recyclerView.post {
+            val galleryWidth = recyclerView.width
+            cardWidth = galleryWidth - 2 * (pagePadding + leftCardShowWidth).toFloat()
+                .dp2px(recyclerView.context)
+        }
+        recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                super.onScrolled(recyclerView, dx, dy)
+                // dx>0则表示右滑, dx<0表示左滑, dy<0表示上滑, dy>0表示下滑
+                if (dx != 0) {
+                    currentItemOffset += dx
+
+                    currentItemPos = currentItemOffset / cardWidth
+
+                    val offset = currentItemOffset - currentItemPos * cardWidth
+                    val percent = max(abs(offset) * 1.0 / cardWidth, 0.0001).toFloat()
+
+                    var leftView: View? = null
+                    var rightView: View? = null
+
+                    recyclerView.layoutManager?.apply {
+                        if (currentItemPos > 0) {
+                            leftView = findViewByPosition(currentItemPos - 1)
+                        }
+                        val currentView = findViewByPosition(currentItemPos)
+                        recyclerView.adapter?.apply {
+                            if (currentItemPos < itemCount - 1) {
+                                rightView = findViewByPosition(currentItemPos + 1)
+                            }
+                        }
+
+                        leftView?.apply {
+                            scaleY = (1 - scale) * percent + scale
+                        }
+                        currentView?.apply {
+                            scaleY = (scale - 1) * percent + 1
+                        }
+                        rightView?.apply {
+                            scaleY = (1 - scale) * percent + scale
+                        }
+                    }
+                }
+            }
+        })
+        snapHelper.attachToRecyclerView(recyclerView)
+    }
+
+    fun getCurrentIndex(): Int {
+        return currentItemPos
+    }
+}

lite/src/main/java/com/pengxh/kt/lite/widget/audio/AudioPlayerView.kt

@@ -46,6 +46,7 @@ class AudioPlayerView(context: Context, attrs: AttributeSet) : AppCompatTextView
 
     private fun initMediaPlayer() {
         mediaPlayer = MediaPlayer()
+        //此时MediaPlayer进入Idle状态，不能进行任何操作，setDataSource会让播放器从Idle进入Loaded状态
         mediaPlayer?.apply {
             val inputStream = FileInputStream(audioSource)
             setDataSource(inputStream.fd)
@@ -67,10 +68,6 @@ class AudioPlayerView(context: Context, attrs: AttributeSet) : AppCompatTextView
                     "$m:$s"
                 }
             }
-
-            setOnCompletionListener {
-                stopAnimation()
-            }
         }
     }