fix(ios): multitap consistency after new-lines

ios/engine/KMEI/KeymanEngine/Classes/Keyboard/InputViewController.swift

@@ -317,7 +317,7 @@ open class InputViewController: UIInputViewController, KeymanWebDelegate {
 
       let range = NSRange(location: before.unicodeScalars.count, length: 0)
 
-      self.setContextState(text: contextWindowText, range: range)
+      self.setContextState(text: contextWindowText, range: range, doSync: true)
     }
 
     updater(preCaretContext, postCaretContext)
@@ -606,7 +606,7 @@ open class InputViewController: UIInputViewController, KeymanWebDelegate {
    * will be expecting SMP-aware measurements.  Swift's `.unicodeScalars`
    * property on `String`s lines up best with this.
    */
-  func setContextState(text: String?, range: NSRange) {
+  func setContextState(text: String?, range: NSRange, doSync: Bool = false) {
     // 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*/ ]
@@ -626,10 +626,7 @@ open class InputViewController: UIInputViewController, KeymanWebDelegate {
       selRange = NSRange(location: selRange.location - 1, length: selRange.length)
     }
 
-    keymanWeb.setText(context)
-    if range.location != NSNotFound {
-      keymanWeb.setCursorRange(selRange)
-    }
+    keymanWeb.setContext(text: context, range: selRange, doSync: doSync)
   }
 
   func resetKeyboardState() {

ios/engine/KMEI/KeymanEngine/Classes/Keyboard/KeymanWebViewController.swift

@@ -223,14 +223,7 @@ extension KeymanWebViewController {
     setSpacebarText(userData.optSpacebarText)
   }
 
-  func setCursorRange(_ range: NSRange) {
-    if range.location != NSNotFound {
-      webView!.evaluateJavaScript("setCursorRange(\(range.location),\(range.length));", completionHandler: nil)
-      self.currentCursorRange = range
-    }
-  }
-
-  func setText(_ text: String?) {
+  func setContext(text: String?, range: NSRange?, doSync: Bool = false) {
     var text = text ?? ""
 
     // Remove any system-added LTR/RTL marks.
@@ -246,7 +239,16 @@ extension KeymanWebViewController {
       let jsonText = jsonString[start..<end]
 
       self.currentText = String(jsonText)
-      webView!.evaluateJavaScript("setKeymanVal(\"\(jsonText)\");", completionHandler: nil)
+
+      var finalRange = range ?? self.currentCursorRange ?? nil
+      self.currentCursorRange = finalRange
+
+      //
+      if (finalRange?.location ?? NSNotFound) != NSNotFound {
+        webView!.evaluateJavaScript("setKeymanContext(\"\(jsonText)\", \(doSync ? "true" : "false"), \(finalRange!.location), \(finalRange!.length));", completionHandler: nil)
+      } else {
+        webView!.evaluateJavaScript("setKeymanContext(\"\(jsonText)\", \(doSync ? "true" : "false"));", completionHandler: nil)
+      }
     } catch {
       os_log("%{public}s", log: KeymanEngineLogger.engine, type: .error, error.localizedDescription)
       SentryManager.capture(error.localizedDescription)
@@ -363,7 +365,7 @@ extension KeymanWebViewController {
       if let packageID = lexicalModel.packageID {
         event.extra?["package"] = packageID
       }
-      
+
       os_log("%{public}s: %{public}s", log: KeymanEngineLogger.resources, type: .error, errorMessage, lexicalModel.id)
       SentryManager.capture(event)
       throw KeyboardError.fileMissing
@@ -572,7 +574,7 @@ extension KeymanWebViewController: WKScriptMessageHandler {
       // This may need filtering for proper use with Sentry?
       // Then again, if KMW is logging it... we already have to worry
       // about it showing up in Web-oriented Sentry logs.
-      
+
       let logMessage = "KMW Log: \(message)"
       os_log("%{public}s", log: KeymanEngineLogger.engine, type: .info, logMessage)
       SentryManager.breadcrumb(logMessage)
@@ -672,10 +674,7 @@ extension KeymanWebViewController: KeymanWebDelegate {
     resizeKeyboard()
 
     // There may have been attempts to set these values before the keyboard loaded!
-    self.setText(self.currentText)
-    if let cursorRange = self.currentCursorRange {
-      self.setCursorRange(cursorRange)
-    }
+    self.setContext(text: self.currentText, range: self.currentCursorRange)
 
     var newKb = Manager.shared.currentKeyboard
 

ios/engine/KMEI/KeymanEngine/Classes/TextField.swift

@@ -19,7 +19,6 @@ public class TextField: UITextField, KeymanResponder {
   public var isInputClickSoundEnabled = true
 
   private var delegateProxy: TextFieldDelegateProxy!
-  private var shouldUpdateKMText = false
 
   private var keyboardChangedObserver: NotificationObserver?
 
@@ -52,8 +51,6 @@ public class TextField: UITextField, KeymanResponder {
 
     self.inputView = Manager.shared.inputViewController.view
 
-    NotificationCenter.default.addObserver(self, selector: #selector(self.textFieldTextDidChange),
-                                           name: UITextField.textDidChangeNotification, object: self)
     keyboardChangedObserver = NotificationCenter.default.addObserver(forName: Notifications.keyboardChanged,
                                                                      observer: self,
                                                                      function: TextField.keyboardChanged)
@@ -155,19 +152,6 @@ public class TextField: UITextField, KeymanResponder {
   @objc func enableInputClickSound() {
     isInputClickSoundEnabled = true
   }
-
-  @objc func textFieldTextDidChange(_ notification: Notification) {
-    if shouldUpdateKMText {
-      // Catches copy/paste operations
-      let textRange = selectedTextRange!
-      let newRange = NSRange(location: offset(from: beginningOfDocument, to: textRange.start),
-                             length: offset(from: textRange.start, to: textRange.end))
-
-      Manager.shared.setContextState(text: text, range: newRange)
-      // This is called when editing in-app; do not reset context here.
-      shouldUpdateKMText = false
-    }
-  }
 }
 
 extension KeymanResponder where Self: TextField {
@@ -196,12 +180,6 @@ extension KeymanResponder where Self: TextField {
 
 // MARK: - UITextFieldDelegate
 extension TextField: UITextFieldDelegate {
-  public func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange,
-                        replacementString string: String) -> Bool {
-    shouldUpdateKMText = true // Enable text update to catch copy/paste operations
-    return true
-  }
-
   public func textFieldShouldClear(_ textField: UITextField) -> Bool {
     if textField == self {
       Manager.shared.clearText()

ios/engine/KMEI/KeymanEngine/Classes/TextView.swift

@@ -262,22 +262,6 @@ extension TextView: UITextViewDelegate {
     os_log("%{public}s", log:KeymanEngineLogger.ui, type: .debug, messageTwo)
   }
 
-  public func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange,
-                       replacementText text: String) -> Bool {
-    // Enable text update to catch copy/paste operations
-    shouldUpdateKMText = true
-    return true
-  }
-
-  public func textViewDidChange(_ textView: UITextView) {
-    if shouldUpdateKMText {
-      // Catches copy/paste operations
-      Manager.shared.setContextState(text: textView.text, range: textView.selectedRange)
-      // This is called when editing in-app; do not reset context here.
-      shouldUpdateKMText = false
-    }
-  }
-
   public func textViewShouldEndEditing(_ textView: UITextView) -> Bool {
     if textView == self {
       resignFirstResponder()

ios/engine/KMEI/KeymanEngine/resources/Keyman.bundle/Contents/Resources/ios-host.js

@@ -276,33 +276,21 @@ function doResetContext() {
     keyman.resetContext();
 }
 
-function setCursorRange(pos, length) {
-    var context = keyman.context;
-
-    //console.log('setCursorRange('+pos+', '+length+')');
-
-    var start = pos;
-    var end = pos + length;
-
-    if(context.selStart != start || context.selEnd != end) {
-      keyman.context.setSelection(start, end);
-      keyman.resetContext();
-    }
-}
-
-function setKeymanVal(text) {
-    //console.log('setKeymanVal('+JSON.stringify(text)+')');
-
+function setKeymanContext(text, doSync, selStart, selLength) {
+    // console.log(`setKeymanContext(${JSON.stringify(text)}, ${doSync}, ${pos}, ${length})`);
     if(text == undefined) {
         text = '';
     }
 
-    if(keyman.context.getText() != text) {
-        keyman.context.setText(text);
+    // Both pos + length are optional parameters.
+    // undefined + <number> => NaN; undefined + undefined => NaN.
+    let selEnd = selStart + selLength;
+    selEnd = isNaN(selEnd) ? undefined : selEnd;
+
+    const shouldReset = keyman.context.updateContext(text, selStart, selEnd);
+    if(!doSync || shouldReset) {
         keyman.resetContext();
     }
-
-    return keyman.context.getText();
 }
 
 function executePopupKey(keyID, keyText) {

web/src/app/webview/src/configuration.ts

@@ -58,13 +58,6 @@ export class WebviewConfiguration extends EngineConfiguration {
 
     return baseReport;
   }
-
-  onRuleFinalization(ruleBehavior: RuleBehavior) {
-    if(!isEmptyTransform(ruleBehavior.transcription?.transform)) {
-      const transform = ruleBehavior.transcription.transform;
-      this.oninserttext(transform.deleteLeft, transform.insert, transform.deleteRight ?? 0);
-    }
-  }
 }
 
 export interface WebviewInitOptionSpec extends InitOptionSpec {

web/src/app/webview/src/contextManager.ts

@@ -1,12 +1,13 @@
-import { type Keyboard, Mock, OutputTarget } from '@keymanapp/keyboard-processor';
+import { type Keyboard, Mock, OutputTarget, Transcription, findCommonSubstringEndIndex } from '@keymanapp/keyboard-processor';
 import { KeyboardStub } from 'keyman/engine/package-cache';
 import { ContextManagerBase, ContextManagerConfiguration } from 'keyman/engine/main';
 import { WebviewConfiguration } from './configuration.js';
 
 export type OnInsertTextFunc = (deleteLeft: number, text: string, deleteRight: number) => void;
 
-class ContextHost extends Mock {
+export class ContextHost extends Mock {
   readonly oninserttext?: OnInsertTextFunc;
+  private savedState: Mock;
 
   constructor(oninserttext: OnInsertTextFunc) {
     super();
@@ -15,21 +16,70 @@ class ContextHost extends Mock {
 
   apply(transform: Transform): void {
     super.apply(transform);
+    this.updateHost();
+  }
 
-    // Signal the necessary text changes to the embedding app, if it exists.
-    if(this.oninserttext) {
-      this.oninserttext(transform.deleteLeft, transform.insert, transform.deleteRight);
+  updateHost(transcription?: Transcription): void {
+    const savedState = this.savedState;
+
+    if(this.savedState) {
+      let transform = null;
+
+      if(transcription) {
+        const preInput = transcription.preInput;
+        // If our saved state matches the `preInput` from the incoming transcription, just reuse its transform.
+        // Will generally not match during multitap operations, though.
+        //
+        // Helps ensure backspaces pass through even if we don't currently have text available in context for them.
+        if(preInput.text == savedState.text && preInput.selStart == savedState.selStart && preInput.selEnd == savedState.selEnd) {
+          transform = transcription.transform;
+        }
+      }
+
+      transform ||= this.buildTransformFrom(this.savedState);
+
+      // Signal the necessary text changes to the embedding app, if it exists.
+      if(this.oninserttext) {
+        this.oninserttext(transform.deleteLeft, transform.insert, transform.deleteRight);
+      }
     }
+
+    // Save the current context state for use in future diffs.
+    this.savedState = Mock.from(this);
   }
 
   restoreTo(original: OutputTarget): void {
-    const reversionTransform = original.buildTransformFrom(this);
-
+    this.savedState = Mock.from(this);
     super.restoreTo(original);
+  }
+
+  updateContext(text: string, selStart: number, selEnd: number): boolean {
+    let shouldResetContext = false;
+    if(text != this.text) {
+      let tempMock = new Mock(text, selStart ?? text._kmwLength(), selEnd ?? text._kmwLength());
+
+      let newLeft = tempMock.getTextBeforeCaret();
+      let oldLeft = this.getTextBeforeCaret();
 
-    if(this.oninserttext) {
-      this.oninserttext(reversionTransform.deleteLeft, reversionTransform.insert, reversionTransform.deleteRight);
+      let unexpectedBeforeCharCount = findCommonSubstringEndIndex(newLeft, oldLeft, true) + 1;
+      shouldResetContext = !!unexpectedBeforeCharCount;
     }
+
+    if(shouldResetContext) {
+      this.text = text;
+    }
+
+    if(selStart === undefined || selEnd === undefined) {
+      // Regardless of keyboard, we should check the SMP-aware length of the string.
+      // Our host app will not know whether or not the keyboard uses SMP chars,
+      // and we want a consistent interface for context synchronization between
+      // host app + app/webview KMW.
+      this.setSelection(this.text._kmwLength());
+    }
+
+    this.savedState = Mock.from(this);
+
+    return shouldResetContext;
   }
 
   // In app/webview, apps are expected to immediately update the selection range AFTER
@@ -40,7 +90,8 @@ class ContextHost extends Mock {
     // Our host app will not know whether or not the keyboard uses SMP chars,
     // and we want a consistent interface for context synchronization between
     // host app + app/webview KMW.
-    this.setSelection(this.text.kmwLength());
+    this.setSelection(this.text._kmwLength());
+    this.savedState = Mock.from(this);
   }
 }
 

web/src/app/webview/src/keymanEngine.ts

@@ -1,11 +1,11 @@
-import { DefaultRules, DeviceSpec } from '@keymanapp/keyboard-processor'
+import { DefaultRules, DeviceSpec, RuleBehavior, isEmptyTransform } from '@keymanapp/keyboard-processor'
 import { KeymanEngine as KeymanEngineBase, KeyboardInterface } from 'keyman/engine/main';
 import { AnchoredOSKView, ViewConfiguration, StaticActivator } from 'keyman/engine/osk';
 import { getAbsoluteX, getAbsoluteY } from 'keyman/engine/dom-utils';
 import { type KeyboardStub, toPrefixedKeyboardId, toUnprefixedKeyboardId } from 'keyman/engine/package-cache';
 
 import { WebviewConfiguration, WebviewInitOptionDefaults, WebviewInitOptionSpec } from './configuration.js';
-import ContextManager from './contextManager.js';
+import ContextManager, { ContextHost } from './contextManager.js';
 import PassthroughKeyboard from './passthroughKeyboard.js';
 import { buildEmbeddedGestureConfig, setupEmbeddedListeners } from './oskConfiguration.js';
 
@@ -15,6 +15,11 @@ export default class KeymanEngine extends KeymanEngineBase<WebviewConfiguration,
   // be compiled down to an IIFE.
   constructor(worker: Worker, sourceUri: string) {
     const config = new WebviewConfiguration(sourceUri);  // currently set to perform device auto-detect.
+
+    config.onRuleFinalization = (ruleBehavior: RuleBehavior) => {
+      (this.context as ContextHost).updateHost(ruleBehavior.transcription);
+    }
+
     config.stubNamespacer = (stub) => {
       // If the package has not yet been applied as namespacing...
       if(stub.KP && stub.KI.indexOf(`${stub.KP}::`) == -1) {