Update to our keyboard input.

Our improved IME support came with a downside, now things like <space><space>
become <space><dot> if the user has turned this on globally on iOS.

Which is great for sending messages, but terrible for a Unix shell, or for
Python users.

This patch covers two problems: that the input accessories went behind the back
of our backing store, so it was not aware of the new inserted character (so ps
aux<space>|<space> was seem by the IME system as <space><space> replacing the
"|" with a ".".

The other problem is the more fundamental issue which is that <space><space>
should be intercepted to prevent the system from sending a backspace, removing
the space and adding the period.

Author: migueldeicaza

Sources/SwiftTerm/iOS/iOSAccessoryView.swift

@@ -65,13 +65,21 @@ public class TerminalAccessory: UIInputView, UIInputViewAudioFeedback {
         #endif
         terminalView?.send (data)
     }
+
+    func clickAndInsertText (_ text: String)
+    {
+        #if os(iOS)
+        UIDevice.current.playInputClick()
+        #endif
+        terminalView?.insertTextFromAccessory(text)
+    }
 
     @objc func esc (_ sender: AnyObject) { clickAndSend ([0x1b]) }
     @objc func tab (_ sender: AnyObject) { clickAndSend ([0x9]) }
-    @objc func tilde (_ sender: AnyObject) { clickAndSend ([UInt8 (ascii: "~")]) }
-    @objc func pipe (_ sender: AnyObject) { clickAndSend ([UInt8 (ascii: "|")]) }
-    @objc func slash (_ sender: AnyObject) { clickAndSend ([UInt8 (ascii: "/")]) }
-    @objc func dash (_ sender: AnyObject) { clickAndSend ([UInt8 (ascii: "-")]) }
+    @objc func tilde (_ sender: AnyObject) { clickAndInsertText ("~") }
+    @objc func pipe (_ sender: AnyObject) { clickAndInsertText ("|") }
+    @objc func slash (_ sender: AnyObject) { clickAndInsertText ("/") }
+    @objc func dash (_ sender: AnyObject) { clickAndInsertText ("-") }
     @objc func f1 (_ sender: AnyObject) { clickAndSend (EscapeSequences.cmdF[0]) }
     @objc func f2 (_ sender: AnyObject) { clickAndSend (EscapeSequences.cmdF[1]) }
     @objc func f3 (_ sender: AnyObject) { clickAndSend (EscapeSequences.cmdF[2]) }

Sources/SwiftTerm/iOS/iOSTerminalView.swift

@@ -173,6 +173,7 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
 
     // We use this as temporary storage for UITextInput, which we send to the terminal on demand
     var textInputStorage: String = ""
+    var pendingAutoPeriodDeleteWasSpace: Bool = false
 
     // This tracks the marked text, part of the UITextInput protocol, which is used to flag temporary data entry, that might
     // be removed afterwards by the input system (input methods will insert approximiations, mark and change on demand)
@@ -1092,11 +1093,39 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
         return !textInputStorage.isEmpty
     }
 
-    /*
-        Soft keyboard input. Hardware keyboard text input is delivered here; special keys are handled in pressesBegan.
-    */
-    open func insertText(_ text: String) {
-        //uitiLog("insertText(\(text.debugDescription)) \(textInputStateDescription())")
+    func normalizedAutoPeriodReplacementText(_ text: String, oldText: Substring, rangeToReplace: TextRange) -> String? {
+        if text == ". " && pendingAutoPeriodDeleteWasSpace {
+            pendingAutoPeriodDeleteWasSpace = false
+            return "  "
+        }
+        guard text == ". " else { return nil }
+        guard rangeToReplace.endPosition.offset == textInputStorage.count else { return nil }
+        guard oldText.count <= 2 else { return nil }
+        guard oldText.allSatisfy({ $0 == " " }) else { return nil }
+        if oldText.count == 1 {
+            return "  "
+        }
+        return String(oldText)
+    }
+
+    private func normalizedAutoPeriodInsertionText(_ text: String, rangeToReplace: TextRange, hadPendingAutoPeriodDelete: Bool) -> String? {
+        guard text == ". " else { return nil }
+        if hadPendingAutoPeriodDelete {
+            pendingAutoPeriodDeleteWasSpace = false
+            return "  "
+        }
+        pendingAutoPeriodDeleteWasSpace = false
+        guard rangeToReplace.isEmpty else { return nil }
+        guard rangeToReplace.endPosition.offset == textInputStorage.count else { return nil }
+        guard textInputStorage.last == " " else { return nil }
+        return " "
+    }
+
+    private func commitTextInput(_ text: String, applyControlModifier: Bool) {
+        let hadPendingAutoPeriodDelete = pendingAutoPeriodDeleteWasSpace
+        if text != ". " {
+            pendingAutoPeriodDeleteWasSpace = false
+        }
 
         if tryComposeKoreanFinal(text) {
             return
@@ -1105,29 +1134,46 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
         beginTextInputEdit()
 
         let rangeToReplace = _markedTextRange ?? _selectedTextRange
+        var textToInsert = text
+        if let normalized = normalizedAutoPeriodInsertionText(text, rangeToReplace: rangeToReplace, hadPendingAutoPeriodDelete: hadPendingAutoPeriodDelete) {
+            textToInsert = normalized
+        }
+
         let rangeStartIndex = rangeToReplace.startPosition.offset
-        textInputStorage.replaceSubrange(rangeToReplace.fullRange(in: textInputStorage), with: text)
+        textInputStorage.replaceSubrange(rangeToReplace.fullRange(in: textInputStorage), with: textToInsert)
         _markedTextRange = nil
-        let insertedPosition = TextPosition(offset: rangeStartIndex + text.count)
+        let insertedPosition = TextPosition(offset: rangeStartIndex + textToInsert.count)
         _selectedTextRange = TextRange(from: insertedPosition, to: insertedPosition)
 
         endTextInputEdit()
 
-        if terminalAccessory?.controlModifier ?? false {
-            self.send(applyControlToEventCharacters(text))
+        if applyControlModifier && (terminalAccessory?.controlModifier ?? false) {
+            self.send(applyControlToEventCharacters(textToInsert))
             terminalAccessory?.controlModifier = false
         } else {
-            if text == "\n" {
+            if textToInsert == "\n" {
                 resetInputBuffer()
                 self.send(data: returnByteSequence [0...])
             } else {
-                self.send(txt: text)
+                self.send(txt: textToInsert)
             }
         }
-        
+
         queuePendingDisplay()
     }
 
+    func insertTextFromAccessory(_ text: String) {
+        commitTextInput(text, applyControlModifier: false)
+    }
+
+    /*
+        Soft keyboard input. Hardware keyboard text input is delivered here; special keys are handled in pressesBegan.
+    */
+    open func insertText(_ text: String) {
+        //uitiLog("insertText(\(text.debugDescription)) \(textInputStateDescription())")
+        commitTextInput(text, applyControlModifier: true)
+    }
+
     // this is necessary because something in the iOS IME seems to prevent
     // the sequence  "ㅇ", "ㅜ", "ㅇ" from becoming "웅", and instead
     // it becomes "우" followed by "ㅇ"
@@ -1212,6 +1258,7 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
                 // This is the case when the user hits backspace, but there is no text in the
                 // text input buffer.  This happens for example when text has been pasted.
                 // In that scenario, we should just send the backspace character to the terminal
+                pendingAutoPeriodDeleteWasSpace = false
                 self.send ([backspaceSendsControlH ? 8 : 0x7f])
                 uitiLog("deleteBackward() no text to delete, sending backspace")
                 return
@@ -1220,11 +1267,16 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
             beginTextInputEdit()
 
             rangeStartIndex -= 1
-            textInputStorage.remove(at: textInputStorage.index(textInputStorage.startIndex, offsetBy: rangeStartIndex))
+            let deleteIndex = textInputStorage.index(textInputStorage.startIndex, offsetBy: rangeStartIndex)
+            let deletedChar = textInputStorage[deleteIndex]
+            let deletingAtEnd = rangeStartPosition.offset == textInputStorage.count
+            pendingAutoPeriodDeleteWasSpace = deletingAtEnd && deletedChar == " " && _markedTextRange == nil
+            textInputStorage.remove(at: deleteIndex)
             rangeStartPosition = TextPosition(offset: rangeStartIndex)
 
             self.send ([backspaceSendsControlH ? 8 : 0x7f])
         } else {
+            pendingAutoPeriodDeleteWasSpace = false
             beginTextInputEdit()
             // Send as many backspaces that are in the range to delete. When on auto-repeat, after a some time
             // pressing the backspace, it will delete chunks of text at a time.

Sources/SwiftTerm/iOS/iOSTextInput.swift

@@ -114,25 +114,32 @@ extension TerminalView: UITextInput {
 
         // Send the edits to the terminal
         // Delete the old by sending as many backspaces as needed
-        let oldText = textInputStorage [r.fullRange(in: textInputStorage)]
+        let oldText = textInputStorage[r.fullRange(in: textInputStorage)]
+        if text != ". " {
+            pendingAutoPeriodDeleteWasSpace = false
+        }
+        var replacementText = text
+        if let normalized = normalizedAutoPeriodReplacementText(text, oldText: oldText, rangeToReplace: r) {
+            replacementText = normalized
+        }
         let backspaces = oldText.count
         for _ in 0..<backspaces {
             self.send ([0x7f])
         }
-        self.send (txt: text)
+        self.send (txt: replacementText)
 
         let insertionIndex = r.startPosition.offset
-        textInputStorage.replaceSubrange(r.fullRange(in: textInputStorage), with: text)
+        textInputStorage.replaceSubrange(r.fullRange(in: textInputStorage), with: replacementText)
         if r.endPosition.offset <= _selectedTextRange.startPosition.offset {
             let selectionOffset = _selectedTextRange.startPosition.offset - insertionIndex
-            let newSelectionOffset = selectionOffset - r.length + text.count
+            let newSelectionOffset = selectionOffset - r.length + replacementText.count
             let newSelectionIndex = newSelectionOffset + insertionIndex
             _selectedTextRange = TextRange(from: TextPosition(offset:newSelectionIndex), 
                                             to: TextPosition(offset: newSelectionIndex + _selectedTextRange.length))
         } else if r.startPosition.offset >= _selectedTextRange.endPosition.offset {
             // NOOP
         } else {
-            let insertionEndPosition = TextPosition(offset:insertionIndex + text.count)            
+            let insertionEndPosition = TextPosition(offset:insertionIndex + replacementText.count)            
             _selectedTextRange = TextRange(from: insertionEndPosition,  to: insertionEndPosition)
         }
 
@@ -219,6 +226,7 @@ extension TerminalView: UITextInput {
     {
         uitiLog("resetInputBuffer() from \(loc) \(textInputStateDescription())")
         beginTextInputEdit()
+        pendingAutoPeriodDeleteWasSpace = false
         textInputStorage = ""
         _selectedTextRange = TextRange (from: TextPosition(offset: 0), to: TextPosition(offset: 0))
         _markedTextRange = nil