From dbbeccebdb3eb8860f2da9e36f9b5d6b2dbe5f04 Mon Sep 17 00:00:00 2001
From: jahorton <jahorton@sil.org>
Date: Fri, 3 May 2019 12:43:45 +0700
Subject: [PATCH] Filters out prefixed LTR/RTL marks from context.

---
 .../Classes/InputViewController.swift         | 42 ++++++++++++-------
 .../Classes/KeymanWebViewController.swift     |  6 +++
 .../KMEI/KeymanEngine/Classes/Manager.swift   |  8 +---
 .../KMEI/KeymanEngine/Classes/TextField.swift | 17 +++-----
 .../KMEI/KeymanEngine/Classes/TextView.swift  | 11 ++---
 5 files changed, 43 insertions(+), 41 deletions(-)

diff --git a/ios/engine/KMEI/KeymanEngine/Classes/InputViewController.swift b/ios/engine/KMEI/KeymanEngine/Classes/InputViewController.swift
index a7ef750489..ba94511b58 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/InputViewController.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/InputViewController.swift
@@ -201,8 +201,7 @@ open class InputViewController: UIInputViewController, KeymanWebDelegate {
       newRange = context.startIndex..<context.startIndex
     }
 
-    setText(context)
-    setSelectionRange(NSRange(newRange, in: context), manually: false)
+    setContextState(text: context, range: NSRange(newRange, in: context))
   }
 
   func insertText(_ keymanWeb: KeymanWebViewController, numCharsToDelete: Int, newText: String) {
@@ -411,24 +410,35 @@ open class InputViewController: UIInputViewController, KeymanWebDelegate {
   func showHelpBubble(afterDelay delay: TimeInterval) {
     keymanWeb.showHelpBubble(afterDelay: delay)
   }
-  
-//  func setCursorRange(_ range: NSRange) {
-//    keymanWeb.setCursorRange(range)
-//  }
-  
-  func setText(_ text: String?) {
-    keymanWeb.setText(text)
-  }
-  
+
   func clearText() {
-    setText(nil)
-    setSelectionRange(NSRange(location: 0, length: 0), manually: true)
+    setContextState(text: nil, range: NSRange(location: 0, length: 0))
     log.info("Cleared text.")
   }
-  
-  func setSelectionRange(_ range: NSRange, manually: Bool) {
+ 
+  func setContextState(text: String?, range: NSRange) {
+    // Check for any LTR or RTL marks at the context's start; if they exist, we should
+    // offset the selection range.
+    let characterOrderingChecks = [ "\u{200e}" /*LTR*/, "\u{202e}" /*RTL 1*/, "\u{200f}" /*RTL 2*/ ]
+    var offsetPrefix = false;
+    
+    let context = text ?? ""
+    
+    for codepoint in characterOrderingChecks {
+      if(context.hasPrefix(codepoint)) {
+        offsetPrefix = true;
+        break;
+      }
+    }
+    
+    var selRange = range;
+    if(offsetPrefix) { // If we have a character ordering mark, offset range location to hide it.
+      selRange = NSRange(location: selRange.location - 1, length: selRange.length)
+    }
+    
+    keymanWeb.setText(context)
     if range.location != NSNotFound {
-      keymanWeb.setCursorRange(range)
+      keymanWeb.setCursorRange(selRange)
     }
   }
   
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/KeymanWebViewController.swift b/ios/engine/KMEI/KeymanEngine/Classes/KeymanWebViewController.swift
index 5a226db84b..830dd233cd 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/KeymanWebViewController.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/KeymanWebViewController.swift
@@ -184,6 +184,12 @@ extension KeymanWebViewController {
 
   func setText(_ text: String?) {
     var text = text ?? ""
+    // Remove any system-added LTR/RTL marks.
+    text = text.replacingOccurrences(of: "\u{200e}", with: "") // Unicode's LTR codepoint
+    text = text.replacingOccurrences(of: "\u{200f}", with: "") // Unicode's RTL codepoint (v1)
+    text = text.replacingOccurrences(of: "\u{202e}", with: "") // Unicode's RTL codepoint (v2)
+
+    // JavaScript escape-sequence encodings.
     text = text.replacingOccurrences(of: "\\", with: "\\\\")
     text = text.replacingOccurrences(of: "'", with: "\\'")
     text = text.replacingOccurrences(of: "\n", with: "\\n")
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift b/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
index 9f7ba5d85b..385cbe82ad 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/Manager.swift
@@ -903,16 +903,12 @@ public class Manager: NSObject, HTTPDownloadDelegate, UIGestureRecognizerDelegat
     Manager.shared.inputViewController.resetKeyboardState()
   }
 
-  func setText(_ text: String?) {
-    inputViewController.setText(text)
-  }
-
   func clearText() {
     inputViewController.clearText()
   }
 
-  func setSelectionRange(_ range: NSRange, manually: Bool) {
-    inputViewController.setSelectionRange(range, manually: manually)
+  func setContextState(text: String?, range: NSRange) {
+    inputViewController.setContextState(text: text, range: range)
   }
   
   var vibrationSupportLevel: VibrationSupport {
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/TextField.swift b/ios/engine/KMEI/KeymanEngine/Classes/TextField.swift
index 80453e97d5..ad964d59b0 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/TextField.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/TextField.swift
@@ -112,11 +112,11 @@ public class TextField: UITextField, KeymanResponder {
         super.text = ""
       }
 
-      Manager.shared.setText(self.text)
       let textRange = selectedTextRange ?? UITextRange()
       let newRange = NSRange(location: offset(from: beginningOfDocument, to: textRange.start),
                              length: offset(from: textRange.start, to: textRange.end))
-      Manager.shared.setSelectionRange(newRange, manually: false)
+
+      Manager.shared.setContextState(text: self.text, range: newRange)
     }
   }
 
@@ -127,7 +127,8 @@ public class TextField: UITextField, KeymanResponder {
       }
       let newRange = NSRange(location: offset(from: beginningOfDocument, to: range.start),
                              length: offset(from: range.start, to: range.end))
-      Manager.shared.setSelectionRange(newRange, manually: false)
+
+      Manager.shared.setContextState(text: self.text, range: newRange)
     }
   }
 
@@ -159,11 +160,11 @@ public class TextField: UITextField, KeymanResponder {
   @objc func textFieldTextDidChange(_ notification: Notification) {
     if shouldUpdateKMText {
       // Catches copy/paste operations
-      Manager.shared.setText(text)
       let textRange = selectedTextRange!
       let newRange = NSRange(location: offset(from: beginningOfDocument, to: textRange.start),
                              length: offset(from: textRange.start, to: textRange.end))
-      Manager.shared.setSelectionRange(newRange, manually: false)
+
+      Manager.shared.setContextState(text: text, range: newRange)
       shouldUpdateKMText = false
     }
   }
@@ -262,12 +263,6 @@ extension TextField: UITextFieldDelegate {
 
     log.debug("TextField: \(self.hashValue) setFont: \(font?.familyName ?? "nil")")
 
-    // copy this textField's text to the webview
-    Manager.shared.setText(text)
-    let textRange = selectedTextRange!
-    let newRange = NSRange(location: offset(from: beginningOfDocument, to: textRange.start),
-                           length: offset(from: textRange.start, to: textRange.end))
-    Manager.shared.setSelectionRange(newRange, manually: false)
     log.debug("TextField: \(self.hashValue) Became first responder. Value: \(String(describing: text))")
   }
 
diff --git a/ios/engine/KMEI/KeymanEngine/Classes/TextView.swift b/ios/engine/KMEI/KeymanEngine/Classes/TextView.swift
index 40e7b8ae28..03024828e7 100644
--- a/ios/engine/KMEI/KeymanEngine/Classes/TextView.swift
+++ b/ios/engine/KMEI/KeymanEngine/Classes/TextView.swift
@@ -109,14 +109,13 @@ public class TextView: UITextView, KeymanResponder {
         super.text = ""
       }
 
-      Manager.shared.inputViewController.setText(self.text)
-      Manager.shared.inputViewController.setSelectionRange(selectedRange, manually: false)
+     Manager.shared.inputViewController.setContextState(text: self.text, range: selectedRange)
     }
   }
 
   public override var selectedTextRange: UITextRange? {
     didSet {
-      Manager.shared.setSelectionRange(selectedRange, manually: false)
+      Manager.shared.setContextState(text: self.text, range: selectedRange)
     }
   }
 
@@ -259,9 +258,6 @@ extension TextView: UITextViewDelegate {
 
     log.debug("TextView: \(self.hashValue) setFont: \(font?.familyName ?? "nil")")
 
-    // copy this textView's text to the webview
-    Manager.shared.setText(text)
-    Manager.shared.setSelectionRange(selectedRange, manually: false)
     log.debug("TextView: \(self.hashValue) Became first responder. Value: \(String(describing: text))")
   }
 
@@ -275,8 +271,7 @@ extension TextView: UITextViewDelegate {
   public func textViewDidChange(_ textView: UITextView) {
     if shouldUpdateKMText {
       // Catches copy/paste operations
-      Manager.shared.setText(textView.text)
-      Manager.shared.setSelectionRange(textView.selectedRange, manually: false)
+      Manager.shared.setContextState(text: textView.text, range: textView.selectedRange)
       shouldUpdateKMText = false
     }
   }