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)

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />

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<Photo>? = 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<Photo> {
            val photos: MutableList<Photo> = ArrayList<Photo>()

            //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<PhotoAdapter.PhotoViewHolder>() {
    private var photos: List<Photo>? = 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<BigImageView>(R.id.image)
            textView = itemView.findViewById<TextView>(R.id.text)
        }
    }

    fun dataChanged(photos: List<Photo>?) {
        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?
)

<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="1dp"
    android:layout_marginTop="1dp"
    android:layout_marginRight="1dp">

    <com.github.piasy.biv.view.BigImageView
        android:id="@+id/image"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        app:failureImage="@android:drawable/ic_dialog_alert"
        app:failureImageInitScaleType="center"
        app:optimizeDisplay="true" />

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/image"
        android:layout_centerHorizontal="true"
        android:maxLines="1"
        android:text="-.-"
        android:textColor="@android:color/black" />
</RelativeLayout>

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