feat: optimize task list item handling (#100)

* feat: optimize task list item handling and enhance markdown rendering

* refactor: remove outdated comments and optimize task list item handling

Author: hryhoriiK97

android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdownManager.kt

@@ -52,14 +52,10 @@ class EnrichedMarkdownManager :
     }
 
     view?.setOnTaskListItemPressCallback { taskIndex, checked, itemText ->
-      val updatedMarkdown =
-        TaskListToggleUtils.toggleAtIndex(
-          view.currentMarkdown,
-          taskIndex,
-          checked,
-        )
+      val newChecked = !checked
+      val updatedMarkdown = TaskListToggleUtils.toggleAtIndex(view.currentMarkdown, taskIndex, newChecked)
       view.setMarkdownContent(updatedMarkdown)
-      emitOnTaskListItemPress(view, taskIndex, !checked, itemText)
+      emitOnTaskListItemPress(view, taskIndex, newChecked, itemText)
     }
 
     view?.setMarkdownContent(markdown ?: "")

android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdownTextManager.kt

@@ -15,6 +15,7 @@ import com.swmansion.enriched.markdown.events.LinkLongPressEvent
 import com.swmansion.enriched.markdown.events.LinkPressEvent
 import com.swmansion.enriched.markdown.events.TaskListItemPressEvent
 import com.swmansion.enriched.markdown.parser.Md4cFlags
+import com.swmansion.enriched.markdown.utils.TaskListTapUtils
 import com.swmansion.enriched.markdown.utils.TaskListToggleUtils
 
 @ReactModule(name = EnrichedMarkdownTextManager.NAME)
@@ -58,14 +59,22 @@ class EnrichedMarkdownTextManager :
     }
 
     view?.setOnTaskListItemPressCallback { taskIndex, checked, itemText ->
-      val updatedMarkdown =
-        TaskListToggleUtils.toggleAtIndex(
-          view.currentMarkdown,
-          taskIndex,
-          checked,
-        )
+      val newChecked = !checked
+
+      val styleConfig = view.markdownStyle
+      val optimizedSuccess =
+        styleConfig != null && TaskListTapUtils.updateTaskListItemCheckedState(view, taskIndex, newChecked, styleConfig)
+
+      if (optimizedSuccess) {
+        emitOnTaskListItemPress(view, taskIndex, newChecked, itemText)
+        return@setOnTaskListItemPressCallback
+      }
+
+      val currentMarkdown = view.currentMarkdown
+      val updatedMarkdown = TaskListToggleUtils.toggleAtIndex(currentMarkdown, taskIndex, newChecked)
       view.setMarkdownContent(updatedMarkdown)
-      emitOnTaskListItemPress(view, taskIndex, !checked, itemText)
+
+      emitOnTaskListItemPress(view, taskIndex, newChecked, itemText)
     }
 
     view?.setMarkdownContent(markdown ?: "No markdown content")

android/src/main/java/com/swmansion/enriched/markdown/utils/TaskListTapUtils.kt

@@ -1,8 +1,16 @@
 package com.swmansion.enriched.markdown.utils
 
+import android.text.Spannable
+import android.text.SpannableStringBuilder
 import android.text.Spanned
+import android.text.style.ForegroundColorSpan
+import android.text.style.StrikethroughSpan
 import android.widget.TextView
+import com.swmansion.enriched.markdown.renderer.SpanStyleCache
+import com.swmansion.enriched.markdown.spans.BaseListSpan
 import com.swmansion.enriched.markdown.spans.TaskListSpan
+import com.swmansion.enriched.markdown.styles.StyleConfig
+import com.swmansion.enriched.markdown.utils.SPAN_FLAGS_EXCLUSIVE_EXCLUSIVE
 
 data class TaskListHitTestResult(
   val taskIndex: Int,
@@ -23,7 +31,8 @@ object TaskListToggleUtils {
 
     val match = matches[index]
     val prefix = match.groupValues[1]
-    val replacement = "$prefix[${if (checked) " " else "x"}]"
+
+    val replacement = "$prefix[${if (checked) "x" else " "}]"
 
     return markdown.replaceRange(match.range, replacement)
   }
@@ -79,4 +88,162 @@ object TaskListTapUtils {
         itemText = itemText,
       )
     }
+
+  fun updateTaskListItemCheckedState(
+    textView: TextView,
+    targetIndex: Int,
+    newChecked: Boolean,
+    styleConfig: StyleConfig,
+  ): Boolean {
+    val text = textView.text
+    if (text !is Spannable) {
+      return false
+    }
+
+    val spannable = SpannableStringBuilder(text)
+    val taskSpans = spannable.getSpans(0, spannable.length, TaskListSpan::class.java)
+
+    val targetSpan = taskSpans.firstOrNull { it.taskIndex == targetIndex }
+    if (targetSpan == null) {
+      return false
+    }
+
+    if (targetSpan.isChecked == newChecked) {
+      return true
+    }
+
+    val spanStart = spannable.getSpanStart(targetSpan)
+    val spanEnd = spannable.getSpanEnd(targetSpan)
+    val itemDepth = targetSpan.depth
+
+    val styleCache = SpanStyleCache(styleConfig)
+    val newTaskSpan =
+      TaskListSpan(
+        taskStyle = styleConfig.taskListStyle,
+        listStyle = styleConfig.listStyle,
+        depth = itemDepth,
+        context = textView.context,
+        styleCache = styleCache,
+        taskIndex = targetIndex,
+        isChecked = newChecked,
+      )
+
+    spannable.removeSpan(targetSpan)
+    spannable.setSpan(newTaskSpan, spanStart, spanEnd, SPAN_FLAGS_EXCLUSIVE_EXCLUSIVE)
+
+    val verifySpans = spannable.getSpans(spanStart, spanEnd, TaskListSpan::class.java)
+    val verifySpan = verifySpans.firstOrNull { it.taskIndex == targetIndex }
+    if (verifySpan == null || verifySpan.isChecked != newChecked) {
+      return false
+    }
+
+    val taskStyle = styleConfig.taskListStyle
+    val checkedTextColor = taskStyle.checkedTextColor
+    val strikethrough = taskStyle.checkedStrikethrough
+
+    val excludedRanges =
+      spannable
+        .getSpans(spanStart, spanEnd, BaseListSpan::class.java)
+        .filter { it.depth > itemDepth }
+        .map { spannable.getSpanStart(it) to spannable.getSpanEnd(it) }
+        .sortedBy { it.first }
+
+    applyDecorationsToRanges(
+      spannable = spannable,
+      spanStart = spanStart,
+      spanEnd = spanEnd,
+      excludedRanges = excludedRanges,
+      isChecked = newChecked,
+      checkedTextColor = checkedTextColor,
+      strikethrough = strikethrough,
+      styleConfig = styleConfig,
+    )
+
+    val imageSpans = text.getSpans(0, text.length, com.swmansion.enriched.markdown.spans.ImageSpan::class.java).toList()
+    val originalSpanStarts = imageSpans.associateWith { text.getSpanStart(it) }
+
+    textView.text = spannable
+
+    val newImageSpans = spannable.getSpans(0, spannable.length, com.swmansion.enriched.markdown.spans.ImageSpan::class.java)
+    imageSpans.forEach { originalSpan ->
+      val matchingSpan =
+        newImageSpans.firstOrNull {
+          it.imageUrl == originalSpan.imageUrl &&
+            spannable.getSpanStart(it) == originalSpanStarts[originalSpan]
+        }
+      (matchingSpan ?: originalSpan).registerTextView(textView)
+    }
+
+    textView.invalidate()
+
+    return true
+  }
+
+  private fun applyDecorationsToRanges(
+    spannable: Spannable,
+    spanStart: Int,
+    spanEnd: Int,
+    excludedRanges: List<Pair<Int, Int>>,
+    isChecked: Boolean,
+    checkedTextColor: Int,
+    strikethrough: Boolean,
+    styleConfig: StyleConfig,
+  ) {
+    var currentPos = spanStart
+    for ((start, end) in excludedRanges) {
+      if (start > currentPos) {
+        if (isChecked) {
+          applyCheckedSpans(spannable, currentPos, start, checkedTextColor, strikethrough)
+        } else {
+          removeCheckedSpans(spannable, currentPos, start, styleConfig)
+        }
+      }
+      currentPos = maxOf(currentPos, end)
+    }
+    if (currentPos < spanEnd) {
+      if (isChecked) {
+        applyCheckedSpans(spannable, currentPos, spanEnd, checkedTextColor, strikethrough)
+      } else {
+        removeCheckedSpans(spannable, currentPos, spanEnd, styleConfig)
+      }
+    }
+  }
+
+  private fun applyCheckedSpans(
+    spannable: Spannable,
+    start: Int,
+    end: Int,
+    color: Int,
+    strikethrough: Boolean,
+  ) {
+    if (color != 0) {
+      spannable.setSpan(ForegroundColorSpan(color), start, end, SPAN_FLAGS_EXCLUSIVE_EXCLUSIVE)
+    }
+    if (strikethrough) {
+      spannable.setSpan(StrikethroughSpan(), start, end, SPAN_FLAGS_EXCLUSIVE_EXCLUSIVE)
+    }
+  }
+
+  private fun removeCheckedSpans(
+    spannable: Spannable,
+    start: Int,
+    end: Int,
+    styleConfig: StyleConfig,
+  ) {
+    val strikethroughSpans = spannable.getSpans(start, end, StrikethroughSpan::class.java)
+    strikethroughSpans.forEach { spannable.removeSpan(it) }
+
+    val colorSpans = spannable.getSpans(start, end, ForegroundColorSpan::class.java)
+    colorSpans.forEach { spannable.removeSpan(it) }
+
+    val listStyleColor = styleConfig.listStyle.color
+    if (listStyleColor != 0) {
+      spannable.setSpan(
+        ForegroundColorSpan(listStyleColor),
+        start,
+        end,
+        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE,
+      )
+    }
+  }
 }

example/src/sampleMarkdown.ts

@@ -98,10 +98,39 @@ The largest terrestrial biome, spanning across **Northern Russia, Canada, and Sc
 
 ---
 
+## Forest Statistics by Type
+
+| Forest Type | Coverage | Annual Rainfall | Biodiversity | Carbon Storage |
+|------------|----------|-----------------|--------------|----------------|
+| Tropical Rainforest | ~7% of land | 80-400 inches | Highest (50%+ species) | High |
+| Temperate Forest | ~16% of land | 30-60 inches | Moderate | Moderate |
+| Boreal Forest (Taiga) | ~11% of land | 15-40 inches | Lower | Highest |
+| Mediterranean Forest | ~2% of land | 20-40 inches | Moderate | Moderate |
+
+---
+
 ## Fascinating Forest Facts
 
 Did you know that trees communicate through an underground network? Scientists call this the \`Wood Wide Web\` — a fungal network connecting tree roots across entire forests.
 
+\`\`\`javascript
+// Example: Tree network simulation
+class TreeNetwork {
+  constructor() {
+    this.trees = [];
+    this.fungalConnections = new Map();
+  }
+  
+  connectTrees(tree1, tree2) {
+    // Trees share nutrients through mycorrhizal networks
+    this.fungalConnections.set(\`\${tree1.id}-\${tree2.id}\`, {
+      nutrientFlow: 'bidirectional',
+      signalTransmission: true
+    });
+  }
+}
+\`\`\`
+
 > Trees share nutrients and information through mycorrhizal networks, essentially "talking" to each other underground.
 
 ### The Science of Tree Communication
@@ -209,14 +238,38 @@ Non-native species disrupt forest ecosystems:
 
 Conservation efforts are critical for preserving these vital ecosystems. Here's how you can help:
 
-1. Support *sustainable forestry* practices
-2. Reduce paper consumption and **recycle**
-3. Plant native trees in your community
-4. Donate to ***conservation organizations***
-5. Choose products with \`FSC certification\`
-6. Advocate for *protected areas*
-7. Reduce your **carbon footprint**
-8. Educate others about forest importance
+### Action Checklist
+
+- [x] Support *sustainable forestry* practices
+  - [x] Research certified sustainable wood products
+  - [ ] Learn about forest management practices
+- [x] Reduce paper consumption and **recycle**
+  - [x] Switch to digital documents when possible
+  - [ ] Set up paper recycling at home
+- [ ] Plant native trees in your community
+  - [ ] Join local tree planting events
+  - [ ] Choose appropriate native species
+- [ ] Donate to ***conservation organizations***
+- [ ] Choose products with \`FSC certification\`
+  - [ ] Look for FSC logo on products
+  - [ ] Support companies with sustainable practices
+- [ ] Advocate for *protected areas*
+- [ ] Reduce your **carbon footprint**
+  - [ ] Use public transportation
+  - [ ] Reduce energy consumption
+- [ ] Educate others about forest importance
+
+### Priority Actions
+
+1. ~~Ignore the problem~~ → **Take immediate action**
+2. Support *sustainable forestry* practices
+3. Reduce paper consumption and **recycle**
+4. Plant native trees in your community
+5. Donate to ***conservation organizations***
+6. Choose products with \`FSC certification\`
+7. Advocate for *protected areas*
+8. Reduce your **carbon footprint**
+9. Educate others about forest importance
 
 > The best time to plant a tree was 20 years ago. The second best time is now.
 >
@@ -233,10 +286,12 @@ Conservation efforts are making a difference:
 
 ### Organizations Making an Impact
 
-- **World Wildlife Fund** — global conservation
-- *Rainforest Alliance* — sustainable agriculture
-- ***The Nature Conservancy*** — land protection
-- One Tree Planted — reforestation projects
+| Organization | Focus Area | Impact |
+|--------------|------------|--------|
+| **World Wildlife Fund** | Global conservation | Protected millions of hectares |
+| *Rainforest Alliance* | Sustainable agriculture | Certified 5M+ hectares |
+| ***The Nature Conservancy*** | Land protection | Protected 125M+ acres |
+| One Tree Planted | Reforestation | Planted 100M+ trees |
 
 ---
 
@@ -251,6 +306,22 @@ Scientists and conservationists are developing innovative approaches to protect
 - ***DNA barcoding*** to track illegal logging
 - AI-powered \`fire prediction\` systems
 
+\`\`\`python
+# Example: Forest monitoring with satellite data
+import satellite_imagery
+
+def detect_deforestation(region):
+    """Monitor forest cover changes using satellite imagery"""
+    current_cover = satellite_imagery.get_forest_cover(region)
+    previous_cover = satellite_imagery.get_historical_cover(region, years_ago=1)
+    
+    deforestation_rate = (previous_cover - current_cover) / previous_cover
+    if deforestation_rate > 0.05:  # 5% threshold
+        alert_conservation_team(region, deforestation_rate)
+    
+    return deforestation_rate
+\`\`\`
+
 ### Restoration Efforts
 
 The UN Decade on Ecosystem Restoration aims to restore **350 million hectares** by 2030: