Merge pull request #584 from wordpress-mobile/issue/555-buffered-action-detection

Issue/555 buffered action detection

Author: daniloercoli

aztec/src/main/kotlin/org/wordpress/aztec/AztecText.kt

@@ -98,13 +98,20 @@ import org.wordpress.aztec.watchers.ParagraphCollapseRemover
 import org.wordpress.aztec.watchers.SuggestionWatcher
 import org.wordpress.aztec.watchers.TextDeleter
 import org.wordpress.aztec.watchers.ZeroIndexContentWatcher
+import org.wordpress.aztec.watchers.event.IEventInjector
+import org.wordpress.aztec.watchers.event.sequence.ObservationQueue
+import org.wordpress.aztec.watchers.event.sequence.known.space.steps.TextWatcherEventInsertText
+import org.wordpress.aztec.watchers.event.text.AfterTextChangedEventData
+import org.wordpress.aztec.watchers.event.text.BeforeTextChangedEventData
+import org.wordpress.aztec.watchers.event.text.OnTextChangedEventData
+import org.wordpress.aztec.watchers.event.text.TextWatcherEvent
 import org.xml.sax.Attributes
 import java.util.ArrayList
 import java.util.Arrays
 import java.util.LinkedList
 
 @Suppress("UNUSED_PARAMETER")
-class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlTappedListener {
+class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlTappedListener, IEventInjector {
     companion object {
         val BLOCK_EDITOR_HTML_KEY = "RETAINED_BLOCK_HTML_KEY"
         val BLOCK_EDITOR_START_INDEX_KEY = "BLOCK_EDITOR_START_INDEX_KEY"
@@ -155,6 +162,7 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
     private var consumeSelectionChangedEvent: Boolean = false
     private var consumeHistoryEvent: Boolean = false
     private var isInlineTextHandlerEnabled: Boolean = true
+    private var bypassObservationQueue: Boolean = false
 
     private var onSelectionChangedListener: OnSelectionChangedListener? = null
     private var onImeBackListener: OnImeBackListener? = null
@@ -205,6 +213,9 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
     var maxImagesWidth: Int = 0
     var minImagesWidth: Int = 0
 
+    var observationQueue: ObservationQueue = ObservationQueue(this)
+    var textWatcherEventBuilder: TextWatcherEvent.Builder = TextWatcherEvent.Builder()
+
     interface OnSelectionChangedListener {
         fun onSelectionChanged(selStart: Int, selEnd: Int)
     }
@@ -434,8 +445,39 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
         DeleteMediaElementWatcher.install(this)
 
         // History related logging has to happen before the changes in [ParagraphCollapseRemover]
-        addTextChangedListener(this)
+        addHistoryLoggingWatcher()
         ParagraphCollapseRemover.install(this)
+
+        // finally add the TextChangedListener
+        addTextChangedListener(this)
+    }
+
+    private fun addHistoryLoggingWatcher() {
+        val historyLoggingWatcher = object : TextWatcher {
+            override fun beforeTextChanged(text: CharSequence, start: Int, count: Int, after: Int) {
+                if (!isViewInitialized) return
+                if (!isTextChangedListenerDisabled() && !consumeHistoryEvent) {
+                    history.beforeTextChanged(toFormattedHtml())
+                }
+            }
+            override fun onTextChanged(text: CharSequence, start: Int, before: Int, count: Int) {
+                if (!isViewInitialized) return
+            }
+            override fun afterTextChanged(text: Editable) {
+                if (isTextChangedListenerDisabled()) {
+                    return
+                }
+
+                isMediaAdded = text.getSpans(0, text.length, AztecMediaSpan::class.java).isNotEmpty()
+
+                if (consumeHistoryEvent) {
+                    consumeHistoryEvent = false
+                }
+
+                history.handleHistory(this@AztecText)
+            }
+        }
+        addTextChangedListener(historyLoggingWatcher)
     }
 
     override fun onWindowFocusChanged(hasWindowFocus: Boolean) {
@@ -800,26 +842,37 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
     override fun beforeTextChanged(text: CharSequence, start: Int, count: Int, after: Int) {
         if (!isViewInitialized) return
 
-        if (!isTextChangedListenerDisabled() && !consumeHistoryEvent) {
-            history.beforeTextChanged(toFormattedHtml())
+        if (!bypassObservationQueue) {
+            // we need to make a copy to preserve the contents as they were before the change
+            val textCopy = SpannableStringBuilder(text)
+            val data = BeforeTextChangedEventData(textCopy, start, count, after)
+            textWatcherEventBuilder.beforeEventData = data
         }
     }
 
     override fun onTextChanged(text: CharSequence, start: Int, before: Int, count: Int) {
         if (!isViewInitialized) return
+
+        if (!bypassObservationQueue) {
+            val textCopy = SpannableStringBuilder(text)
+            val data = OnTextChangedEventData(textCopy, start, before, count)
+            textWatcherEventBuilder.onEventData = data
+        }
     }
 
     override fun afterTextChanged(text: Editable) {
         if (isTextChangedListenerDisabled()) {
             return
         }
 
-        isMediaAdded = text.getSpans(0, text.length, AztecMediaSpan::class.java).isNotEmpty()
+        if (!bypassObservationQueue) {
+            val textCopy = Editable.Factory.getInstance().newEditable(editableText)
+            val data = AfterTextChangedEventData(textCopy)
+            textWatcherEventBuilder.afterEventData = data
 
-        if (consumeHistoryEvent) {
-            consumeHistoryEvent = false
+            // now that we have a full event cycle (before, on, and after) we can add the event to the observation queue
+            observationQueue.add(textWatcherEventBuilder.build())
         }
-        history.handleHistory(this)
     }
 
     fun redo() {
@@ -1046,6 +1099,14 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
         consumeEditEvent = false
     }
 
+    fun disableObservationQueue() {
+        bypassObservationQueue = true
+    }
+
+    fun enableObservationQueue() {
+        bypassObservationQueue = false
+    }
+
     fun isTextChangedListenerDisabled(): Boolean {
         return consumeEditEvent
     }
@@ -1455,4 +1516,17 @@ class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlT
     override fun onUnknownHtmlTapped(unknownHtmlSpan: UnknownHtmlSpan) {
         showBlockEditorDialog(unknownHtmlSpan)
     }
+
+    override fun executeEvent(data: TextWatcherEvent) {
+        disableObservationQueue()
+
+        if (data is TextWatcherEventInsertText) {
+            // here replace the inserted thing with a new "normal" insertion
+            val afterData = data.afterEventData
+            setText(afterData.textAfter)
+            setSelection(data.insertionStart+data.insertionLength)
+        }
+
+        enableObservationQueue()
+    }
 }

aztec/src/main/kotlin/org/wordpress/aztec/watchers/EndOfBufferMarkerAdder.kt

@@ -3,8 +3,8 @@ package org.wordpress.aztec.watchers
 import android.text.Editable
 import android.text.SpannableStringBuilder
 import android.text.TextWatcher
-import android.widget.EditText
 import android.widget.TextView
+import org.wordpress.aztec.AztecText
 import org.wordpress.aztec.Constants
 import org.wordpress.aztec.spans.IAztecBlockSpan
 
@@ -32,7 +32,7 @@ class EndOfBufferMarkerAdder(text: Editable) : TextWatcher {
     }
 
     companion object {
-        fun install(editText: EditText) {
+        fun install(editText: AztecText) {
             editText.addTextChangedListener(EndOfBufferMarkerAdder(editText.text))
         }
 

aztec/src/main/kotlin/org/wordpress/aztec/watchers/ParagraphCollapseAdjuster.kt

@@ -3,7 +3,7 @@ package org.wordpress.aztec.watchers
 import android.text.Editable
 import android.text.Spannable
 import android.text.TextWatcher
-import android.widget.TextView
+import org.wordpress.aztec.AztecText
 import org.wordpress.aztec.spans.IParagraphFlagged
 import org.wordpress.aztec.util.SpanWrapper
 
@@ -46,7 +46,7 @@ class ParagraphCollapseAdjuster : TextWatcher {
     override fun afterTextChanged(s: Editable) {}
 
     companion object {
-        fun install(text: TextView) {
+        fun install(text: AztecText) {
             text.addTextChangedListener(ParagraphCollapseAdjuster())
         }
     }

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/IEventInjector.kt

@@ -0,0 +1,7 @@
+package org.wordpress.aztec.watchers.event
+
+import org.wordpress.aztec.watchers.event.text.TextWatcherEvent
+
+interface IEventInjector {
+    fun executeEvent(data: TextWatcherEvent)
+}

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/buckets/API26Bucket.kt

@@ -0,0 +1,13 @@
+package org.wordpress.aztec.watchers.event.buckets
+
+import org.wordpress.aztec.watchers.event.sequence.known.space.API26InWordSpaceInsertionEvent
+
+class API26Bucket : Bucket() {
+    init {
+        // constructor - here add all identified sequences for this bucket
+        userOperations.add(API26InWordSpaceInsertionEvent())
+        //mUserOperations.add(new ...);
+        //mUserOperations.add(new ...);
+        //mUserOperations.add(new ...);
+    }
+}

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/buckets/Bucket.kt

@@ -0,0 +1,12 @@
+package org.wordpress.aztec.watchers.event.buckets
+
+import org.wordpress.aztec.watchers.event.sequence.UserOperationEvent
+
+import java.util.ArrayList
+
+/*
+    extend from this class to construct a specific bucket
+ */
+abstract class Bucket {
+    val userOperations = ArrayList<UserOperationEvent>()
+}

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/sequence/EventSequence.kt

@@ -0,0 +1,4 @@
+package org.wordpress.aztec.watchers.event.sequence
+
+open class EventSequence<TextWatcherEvent> : ArrayList<TextWatcherEvent>()
+

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/sequence/ObservationQueue.kt

@@ -0,0 +1,63 @@
+package org.wordpress.aztec.watchers.event.sequence
+
+import android.os.Build
+import org.wordpress.aztec.watchers.event.IEventInjector
+import org.wordpress.aztec.watchers.event.buckets.API26Bucket
+import org.wordpress.aztec.watchers.event.text.TextWatcherEvent
+import org.wordpress.aztec.watchers.event.buckets.Bucket
+
+class ObservationQueue(val injector: IEventInjector) : EventSequence<TextWatcherEvent>() {
+    val buckets = ArrayList<Bucket>()
+
+    init {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            buckets.add(API26Bucket())
+        }
+        /*
+            remember to add here any other buckets and init logic as suitable, depending on the context
+         */
+    }
+
+    override fun add(element: TextWatcherEvent): Boolean {
+        synchronized(this@ObservationQueue) {
+            val added: Boolean = super.add(element)
+            if (buckets.size == 0) {
+                return added
+            }
+            if (added) {
+                processQueue()
+            }
+            return added
+        }
+    }
+
+    private fun processQueue() {
+        // here let's check whether our current queue matches / fits any of the installed buckets
+        var foundOnePartialMatch = false
+        for (bucket in buckets) {
+            for (operation in bucket.userOperations) {
+                if (size < operation.sequence.size) {
+                    if (operation.isUserOperationPartiallyObservedInSequence(this)) {
+                        foundOnePartialMatch = true
+                    }
+                } else {
+                    // does this particular event look like a part of any of the user operations as defined in this bucket?
+                    if (operation.isUserOperationObservedInSequence(this)) {
+                        // replace user operation with ONE TextWatcherEvent and inject this one in the actual
+                        // textwatchers
+                        val replacementEvent = operation.buildReplacementEventWithSequenceData(this)
+                        injector.executeEvent(replacementEvent)
+                        clear()
+                    }
+                }
+            }
+        }
+
+        // we didn't find neither a partial match nor a total match, let's just clear the queue
+        if (size > 0 && !foundOnePartialMatch) {
+            // immediately discard the queue
+            clear()
+        }
+    }
+}
+

aztec/src/main/kotlin/org/wordpress/aztec/watchers/event/sequence/UserOperationEvent.kt

@@ -0,0 +1,19 @@
+package org.wordpress.aztec.watchers.event.sequence
+
+import org.wordpress.aztec.watchers.event.text.TextWatcherEvent
+
+abstract class UserOperationEvent(var sequence: EventSequence<TextWatcherEvent> = EventSequence()) {
+
+    fun addSequenceStep(event: TextWatcherEvent) {
+        sequence.add(event)
+    }
+
+    fun clear() {
+        sequence.clear()
+    }
+
+    abstract fun isUserOperationObservedInSequence(sequence: EventSequence<TextWatcherEvent>) : Boolean
+    abstract fun isUserOperationPartiallyObservedInSequence(sequence: EventSequence<TextWatcherEvent>) : Boolean
+    abstract fun buildReplacementEventWithSequenceData(sequence: EventSequence<TextWatcherEvent>) : TextWatcherEvent
+}
+