Merge pull request #2 from jt-gilkeson/feature/support_delete

Added ability to remove photos

gallery/src/main/java/com/jt/gallery/FullScreenView.kt

@@ -4,4 +4,5 @@ interface FullScreenView {
     fun showSystemUI()
     fun hideSystemUI()
     fun isNavigationVisible(): Boolean
+    fun resetAdapter(index: Int)
 }

gallery/src/main/java/com/jt/gallery/GalleryActivity.kt

@@ -11,20 +11,23 @@ import kotlin.collections.ArrayList
 
 private const val PAGER_OFFSCREEN_LIMIT = 10
 
-private const val IMAGE_LIST = "imageList"
 private const val POSITION = "position"
 private const val FULL_BRIGHTNESS = "fullBrightness"
+private const val ALLOW_DELETE = "allowDelete"
 
 class GalleryActivity : AppCompatActivity(), FullScreenView {
 
     companion object {
+        const val IMAGE_LIST = "imageList"
+
         @JvmStatic
         @JvmOverloads
-        fun newIntent(context: Context, imageList: List<String>, currentImage: Int = 0, useFullBrightness: Boolean = false) =
+        fun newIntent(context: Context, imageList: List<String>, currentImage: Int = 0, useFullBrightness: Boolean = false, allowDelete: Boolean = false) =
             Intent(context, GalleryActivity::class.java).apply {
                 putExtra(IMAGE_LIST, ArrayList(imageList))
                 putExtra(POSITION, currentImage)
                 putExtra(FULL_BRIGHTNESS, useFullBrightness)
+                putExtra(ALLOW_DELETE, allowDelete)
             }
     }
 
@@ -37,19 +40,18 @@ class GalleryActivity : AppCompatActivity(), FullScreenView {
         setContentView(R.layout.activity_gallery)
 
         val currentImage: Int
-        val adjustBrightness: Boolean
+        val adjustBrightness = intent.getBooleanExtra(FULL_BRIGHTNESS, false)
+        val allowDelete = intent.getBooleanExtra(ALLOW_DELETE, false)
 
         if (savedInstanceState != null) {
             imageList = savedInstanceState.getStringArrayList(IMAGE_LIST) ?: arrayListOf()
             currentImage = savedInstanceState.getInt(POSITION)
-            adjustBrightness = intent.getBooleanExtra(FULL_BRIGHTNESS, false)
         } else {
             imageList = intent.getStringArrayListExtra(IMAGE_LIST)
             currentImage = intent.getIntExtra(POSITION, 0)
-            adjustBrightness = intent.getBooleanExtra(FULL_BRIGHTNESS, false)
         }
 
-        val galleryAdapter = GalleryAdapter(this, imageList)
+        val galleryAdapter = GalleryAdapter(this, imageList, allowDelete)
 
         galleryViewPager.apply {
             offscreenPageLimit = PAGER_OFFSCREEN_LIMIT
@@ -95,6 +97,17 @@ class GalleryActivity : AppCompatActivity(), FullScreenView {
     override fun isNavigationVisible(): Boolean =
         window.decorView.systemUiVisibility and View.SYSTEM_UI_FLAG_HIDE_NAVIGATION == 0
 
+    override fun resetAdapter(index: Int) {
+        // Need to reset the adapter to update it
+        galleryViewPager.adapter = GalleryAdapter(this, imageList, true)
+        galleryViewPager.currentItem = index
+    }
+
+    override fun onBackPressed() {
+        setResult(RESULT_OK, Intent().putStringArrayListExtra(IMAGE_LIST, imageList))
+        super.onBackPressed()
+    }
+
     private fun setScreenBrightnessTo(brightness: Float) {
         val lp = window.attributes
         if (lp.screenBrightness == brightness) {

gallery/src/main/java/com/jt/gallery/GalleryAdapter.kt

@@ -2,6 +2,7 @@ package com.jt.gallery
 
 import android.graphics.drawable.Drawable
 import android.support.v4.view.PagerAdapter
+import android.support.v7.app.AlertDialog
 import android.util.SparseArray
 import android.view.LayoutInflater
 import android.view.View
@@ -17,7 +18,8 @@ import uk.co.senab.photoview.PhotoViewAttacher
 
 class GalleryAdapter(
     private val view: FullScreenView,
-    private val images: ArrayList<String>
+    private val images: ArrayList<String>,
+    private val allowDelete: Boolean = false
 ) : PagerAdapter() {
     private val views: SparseArray<View> = SparseArray()
 
@@ -42,6 +44,23 @@ class GalleryAdapter(
                     val photoView = PhotoViewAttacher(rootView.galleryImage)
                     photoView.onViewTapListener = tapListener
                     photoView.scaleType = ImageView.ScaleType.FIT_CENTER
+
+                    if (allowDelete) {
+                        photoView.setOnLongClickListener {
+                            AlertDialog.Builder(it.context)
+                                .setMessage(R.string.delete_message)
+                                .setPositiveButton(R.string.delete) { dialog, _ ->
+                                    deleteItem(position)
+                                    dialog.dismiss()
+                                }
+                                .setNegativeButton(android.R.string.cancel) { dialog, _ -> dialog.dismiss() }
+                                .create()
+                                .show()
+
+                            true
+                        }
+                    }
+
                     return false
                 }
 
@@ -67,6 +86,14 @@ class GalleryAdapter(
 
     override fun getCount() = images.size
 
+    private fun deleteItem(position: Int) {
+        images.removeAt(position)
+        views.remove(position)
+        notifyDataSetChanged()
+
+        view.resetAdapter(if (position > images.size - 1) images.size - 1 else position)
+    }
+
     private val tapListener = PhotoViewAttacher.OnViewTapListener { _, _, _ ->
         if (view.isNavigationVisible()) {
             view.hideSystemUI()

gallery/src/main/res/values/strings.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="delete_message">Delete item?</string>
+    <string name="delete">Delete</string>
+</resources>