Preserve selection when updating a gallery

Author: planarvoid

media-placeholders/src/main/java/org/wordpress/aztec/placeholders/PlaceholderManager.kt

@@ -168,9 +168,13 @@ class PlaceholderManager(
         } ?: return false
         if (shouldUpdateItem(currentItem.attributes)) {
             val type = currentItem.attributes.getValue(TYPE_ATTRIBUTE)
+            val selectionStart = aztecText.selectionStart
+            val selectionEnd = aztecText.selectionEnd
+            aztecText.setSelection(aztecText.editableText.getSpanStart(currentItem))
             updateSpan(type, currentItem, updateItem = { attributes, _ ->
                 updateItem(attributes)
             }, type)
+            aztecText.setSelection(selectionStart, selectionEnd)
         } else {
             removeItem(uuid)
         }

media-placeholders/src/test/java/org/wordpress/aztec/placeholders/PlaceholderTest.kt

@@ -143,6 +143,31 @@ class PlaceholderTest {
         }
     }
 
+    @Test
+    @Throws(Exception::class)
+    fun updatePlaceholderAtTheEnd() {
+        runBlocking {
+            val initialHtml = "<p>First Line</p><placeholder uuid=\"uuid123\" type=\"image_with_caption\" src=\"image.jpg;image2.jpg\" caption=\"Caption - 1, 2\" /><p>Second Line</p>"
+            editText.fromHtml(initialHtml)
+            editText.setSelection(editText.editableText.indexOf("First") + 1)
+            val initialSelectionStart = editText.selectionStart
+            val initialSelectionEnd = editText.selectionEnd
+
+            placeholderManager.removeOrUpdate("uuid123", shouldUpdateItem = {
+                true
+            }) { currentAttributes ->
+                val result = mutableMapOf<String, String>()
+                result["src"] = currentAttributes["src"]?.split(";")?.firstOrNull() ?: ""
+                result["caption"] = "Updated caption"
+                result
+            }
+
+            Assert.assertEquals("<p>First Line</p><placeholder src=\"image.jpg\" caption=\"Updated caption\" uuid=\"uuid123\" type=\"image_with_caption\" /><p>Second Line</p>", editText.toHtml())
+            Assert.assertEquals(initialSelectionStart, editText.selectionStart)
+            Assert.assertEquals(initialSelectionEnd, editText.selectionEnd)
+        }
+    }
+
     @Test
     @Throws(Exception::class)
     fun removePlaceholderWhenItShouldNotBeUpdated() {