Android load all photos into RecyclerView,pinch to zoom by ScaleGestureDetector,kotlin(4)

Android load all photos into RecyclerView,pinch to zoom by ScaleGestureDetector,kotlin(4)

import android.content.ContentValues
import android.content.Context
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.util.Log
import android.view.ScaleGestureDetector
import android.view.ScaleGestureDetector.SimpleOnScaleGestureListener
import android.view.View.OnTouchListener
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import java.io.File
import java.text.SimpleDateFormat
import java.util.Date


class MainActivity : AppCompatActivity() {
    private var mPhotos: List? = null
    private var mRecyclerView: RecyclerView? = null
    private var mPhotoAdapter: PhotoAdapter? = null
    private var mLayoutManager: GridLayoutManager? = null
    private var mScaleGestureDetector: ScaleGestureDetector? = null
    private val TAG = "fly"
    private val ZOOM = intArrayOf(3, 5, 9)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.recycler_view)
        mRecyclerView = findViewById(R.id.recycler_view)
        mLayoutManager = GridLayoutManager(this, ZOOM[2])
        mLayoutManager?.orientation = GridLayoutManager.VERTICAL
        mRecyclerView?.setLayoutManager(mLayoutManager)
        mScaleGestureDetector = ScaleGestureDetector(this, object : SimpleOnScaleGestureListener() {
            override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
                Log.d(TAG, "--onScaleBegin--")
                return super.onScaleBegin(detector)
            }

            override fun onScale(detector: ScaleGestureDetector): Boolean {
                Log.d(TAG, "--onScale--")
                return super.onScale(detector)
            }

            override fun onScaleEnd(detector: ScaleGestureDetector) {
                super.onScaleEnd(detector)
                Log.d(TAG, "--onScaleEnd--")
                Log.d(TAG, "TimeDelta-" + detector.timeDelta)
                Log.d(TAG, "ScaleFactor-" + detector.scaleFactor)
                Log.d(TAG, "currentSpan-" + detector.currentSpan)
                scale(detector)
            }

            private fun scale(detector: ScaleGestureDetector): Boolean {
                if (detector.currentSpan > 50 && detector.timeDelta > 10) {
                    val scaleFactor = detector.scaleFactor
                    val curSpanCount = mLayoutManager!!.spanCount
                    Log.d(TAG, "LayoutManager SpanCount()-\$curSpanCount")
                    val curIndex = getSpanCountIndex(curSpanCount)
                    if (scaleFactor < 1) {
                        if (curSpanCount == ZOOM[ZOOM.size - 1]) {
                            return true
                        } else {
                            mLayoutManager!!.spanCount = ZOOM[curIndex + 1]
                        }
                    } else {
                        if (curSpanCount == ZOOM[0]) {
                            return true
                        } else {
                            mLayoutManager!!.spanCount = ZOOM[curIndex - 1]
                        }
                    }
                    mRecyclerView?.setLayoutManager(mLayoutManager)
                    mPhotoAdapter?.dataChanged(mPhotos)

                    return true
                }
                return false
            }
        })

        mRecyclerView?.setOnTouchListener(OnTouchListener { v, event ->
            mScaleGestureDetector!!.onTouchEvent(event)
            false
        })

        mPhotoAdapter = PhotoAdapter(applicationContext)
        mRecyclerView?.setAdapter(mPhotoAdapter)

        CoroutineScope(Dispatchers.IO).launch {
            mPhotos = readAllImage(applicationContext)
            launch(Dispatchers.Main) {
                mPhotoAdapter?.dataChanged(mPhotos)
            }
        }
    }

    private fun getSpanCountIndex(spanCount: Int): Int {
        var index = 0
        for (i in ZOOM.indices) {
            if (spanCount == ZOOM[i]) {
                index = i
            }
        }
        return index
    }

    companion object {
        private fun readAllImage(context: Context): List {
            val photos: MutableList = ArrayList()

            //读取手机图片
            val cursor = context.contentResolver.query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                null,
                null,
                null,
                null
            )
            while (cursor!!.moveToNext()) {
                //图片的路径
                val path =
                    cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA))

                //图片名称
                val name =
                    cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME))

                //图片最后修改日期
                val file = File(path)
                val sdf = SimpleDateFormat("yyyy-MM-dd hh:mm:ss")
                val date = sdf.format(Date(file.lastModified()))

                //图片大小
                val size =
                    cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE))
                val photo = Photo(name, date, size, path, getImageUri(context, path))
                photos.add(photo)
            }
            cursor.close()
            return photos
        }

        private fun getImageUri(context: Context, filePath: String): Uri? {
            val cursor = context.contentResolver.query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                arrayOf(MediaStore.Images.Media._ID),
                MediaStore.Images.Media.DATA + "=? ",
                arrayOf(filePath),
                null
            )
            return if (cursor != null && cursor.moveToFirst()) {
                val id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns._ID))
                val baseUri = Uri.parse("content://media/external/images/media")
                Uri.withAppendedPath(baseUri, "" + id)
            } else {
                val values = ContentValues()
                values.put(MediaStore.Images.Media.DATA, filePath)
                context.contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
            }
        }
    }
}

import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.github.piasy.biv.BigImageViewer
import com.github.piasy.biv.loader.glide.GlideImageLoader
import com.github.piasy.biv.view.BigImageView


class PhotoAdapter(context: Context?) :
    RecyclerView.Adapter() {
    private var photos: List? = null

    init {
        BigImageViewer.initialize(GlideImageLoader.with(context))
    }

    override fun onCreateViewHolder(
        parent: ViewGroup,
        viewType: Int
    ): PhotoViewHolder {
        val view: View =
            LayoutInflater.from(parent.context).inflate(R.layout.photo, parent, false)
        return PhotoViewHolder(view)
    }

    override fun onBindViewHolder(holder: PhotoViewHolder, position: Int) {
        holder.textView.text = position.toString()
        holder.imageView.showImage(photos?.get(position)?.uri)
    }

    override fun getItemCount(): Int {
        return photos?.size ?: 0
    }

    inner class PhotoViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var imageView: BigImageView
        var textView: TextView

        init {
            imageView = itemView.findViewById(R.id.image)
            textView = itemView.findViewById(R.id.text)
        }
    }

    fun dataChanged(photos: List?) {
        this.photos = photos

        notifyDataSetChanged()
    }
}

import android.net.Uri


class Photo(
    //名称
    var name: String, //日期
    var date: String, //大小
    var size: Long,//路径
    var path: String,
    var uri: Uri?
)

Android load all photos into RecyclerView,support pinch to zoom by ScaleGestureDetector,Java(3)_zhangphil的博客-CSDN博客Android RecyclerView的StaggeredGridLayoutManager实现交错排列的子元素分组先看实现的结果如图：设计背景：现在的产品对设计的需求越来越多样化，如附录文章2是典型的联系人分组RecyclerView，子元素排列到一个相同的组，但是有些时候，UI要求把这些元素不是垂直方向的，而是像本文开头的图中所示样式排列，这就需要用StaggeredGridLayoutMa。在处理大图的浏览查看动作过程中，往往还有其他额外的事情需要处理，典型的以微信。https://blog.csdn.net/zhangphil/article/details/130708679