| /* |
| * Copyright 2023 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.graphics.lowlatency |
| |
| import android.content.Context |
| import android.graphics.Canvas |
| import android.graphics.Color |
| import android.os.Build |
| import android.view.MotionEvent |
| import android.view.SurfaceView |
| import androidx.annotation.RequiresApi |
| |
| @RequiresApi(Build.VERSION_CODES.Q) |
| class InkCanvasView(context: Context) : SurfaceView(context) { |
| |
| private var mCanvasFrontBufferedRenderer: CanvasFrontBufferedRenderer<FloatArray>? = null |
| private val mLinesDrawable = LinesDrawable() |
| private val mSceneParams = ArrayList<FloatArray>() |
| private val mCallbacks = object : CanvasFrontBufferedRenderer.Callback<FloatArray> { |
| |
| override fun onDrawFrontBufferedLayer( |
| canvas: Canvas, |
| bufferWidth: Int, |
| bufferHeight: Int, |
| param: FloatArray |
| ) { |
| with(mLinesDrawable) { |
| setBounds(0, 0, bufferWidth, bufferHeight) |
| setLines(param) |
| setColor(Color.CYAN) |
| draw(canvas) |
| } |
| } |
| |
| override fun onDrawMultiBufferedLayer( |
| canvas: Canvas, |
| bufferWidth: Int, |
| bufferHeight: Int, |
| params: Collection<FloatArray> |
| ) { |
| mSceneParams.addAll(params) |
| with(mLinesDrawable) { |
| setBounds(0, 0, bufferWidth, bufferHeight) |
| setColor(Color.MAGENTA) |
| for (param in mSceneParams) { |
| setLines(param) |
| draw(canvas) |
| } |
| } |
| } |
| } |
| |
| private var mPreviousX: Float = 0f |
| private var mPreviousY: Float = 0f |
| private var mCurrentX: Float = 0f |
| private var mCurrentY: Float = 0f |
| |
| init { |
| setOnTouchListener { _, event -> |
| when (event.action) { |
| MotionEvent.ACTION_DOWN -> { |
| requestUnbufferedDispatch(event) |
| mCurrentX = event.x |
| mCurrentY = event.y |
| } |
| MotionEvent.ACTION_MOVE -> { |
| mPreviousX = mCurrentX |
| mPreviousY = mCurrentY |
| mCurrentX = event.x |
| mCurrentY = event.y |
| |
| val line = FloatArray(4).apply { |
| this[0] = mPreviousX |
| this[1] = mPreviousY |
| this[2] = mCurrentX |
| this[3] = mCurrentY |
| } |
| mCanvasFrontBufferedRenderer?.renderFrontBufferedLayer(line) |
| } |
| MotionEvent.ACTION_CANCEL -> { |
| mCanvasFrontBufferedRenderer?.cancel() |
| } |
| MotionEvent.ACTION_UP -> { |
| mCanvasFrontBufferedRenderer?.commit() |
| } |
| } |
| true |
| } |
| } |
| |
| override fun onAttachedToWindow() { |
| super.onAttachedToWindow() |
| mCanvasFrontBufferedRenderer = CanvasFrontBufferedRenderer(this, mCallbacks) |
| } |
| |
| override fun onDetachedFromWindow() { |
| super.onDetachedFromWindow() |
| mCanvasFrontBufferedRenderer?.release(true) |
| mCanvasFrontBufferedRenderer = null |
| } |
| } |
