Implement GoVarnam Inpue Method Engine (#2)

* Fix links
* Improve build script
* Remove individual binaries before new build
* Ignore dylib
* Add govarnam library
* Disable AppSandbox for IME to register NSConnection. Reference: https://blog.inoki.cc/2021/06/19/Write-your-own-IME-on-macOS-1/
* IME works but no candidates yet
* Candidate showing works! Return value from handle is very important!
* Made improvements to candidate shower
* Refactor: Remove unnecessary code
* Remove clientmanager, inputcontroller dependency on lipika-engine
* Cursor can now move left, right
* Set default orientation vertical
* Close window on Escape key
* Select first candidate on enter key press
* Add resources
* Remove duplicate entries because candidatesWindow makes them hidden
* candidate selection change doesn't work
* Moving up/down in candidates window works
* Add more resources
* Select candidate based on cursor in candidate table

.github/README.md

@@ -4,12 +4,23 @@ Easily type Indian languages on macOS using [Varnam transliteration engine](http
 
 Built at FOSSUnited's [FOSSHack21](https://fossunited.org/fosshack/2021/project?project=Type%20Indian%20Languages%20natively%20on%20Mac).
 
-This project is a hard-fork of [lipika-ime](github.com/ratreya/Lipika_IME). Changes made:
+This project is a hard-fork of [lipika-ime](https://github.com/ratreya/Lipika_IME). Changes made:
 * https://github.com/varnamproject/varnam-macOS/pull/1
 
+There aren't many documentation on how to make IMEs for macOS, especially in **English**. Getting started with XCode is also tricky for beginners. Setting up **Lipika** was also difficult.
+
+Resources that helped in making IME on macOS (ordered by most important to the least):
+* https://blog.inoki.cc/2021/06/19/Write-your-own-IME-on-macOS-1/ (The last section is very important!)
+* https://jyhong836.github.io/tech/2015/07/29/add-3rd-part-dynamic-library-dylib-to-xcode-target.html
+* https://github.com/lennylxx/google-input-tools-macos (An IME made 2 months ago, Has GitHub CI builds)
+* https://github.com/nh7a/hiragany (Simple Japanese IME)
+* https://github.com/pkamb/NumberInput_IMKit_Sample/issues/1
+* API Docs: https://developer.apple.com/documentation/inputmethodkit/imkcandidates
+
 ## License
 
 > Copyright (C) 2018 Ranganath Atreya
+>
 > Copyright (C) 2021 Subin Siby
 
 ```
@@ -18,4 +29,4 @@ General Public License as published by the Free Software Foundation; either vers
 or (at your option) any later version.
 
 This program comes with ABSOLUTELY NO WARRANTY; see LICENSE file.
-```
+```

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "GoVarnam/govarnam"]
+	path = GoVarnam/govarnam
+	url = [email protected]:varnamproject/govarnam.git

Application/LiteratorView.swift

@@ -87,7 +87,7 @@ class LiteratorModel: ObservableObject {
                 return self.ante!.anteliterate(lit.finalaizedOutput + lit.unfinalaizedOutput)
             }
         case (0, 1):
-            let override: [String: MappingValue]? = MappingStore.read(schemeName: self.fromScheme, scriptName: self.toScript)
+            let override: [String: MappingValue]? = .read(schemeName: self.fromScheme, scriptName: self.toScript)
             self.trans = try! self.factory.transliterator(schemeName: self.fromScheme, scriptName: self.toScript, mappings: override)
             eval = { (input: String) -> String in
                 _ = self.trans!.reset()

GoVarnam/.gitignore

@@ -0,0 +1 @@
+*.dylib

GoVarnam/Varnam.swift

@@ -0,0 +1,62 @@
+//
+//  Varnam.swift
+//  VarnamIME
+//
+//  Created by Subin on 13/11/21.
+//  Copyright © 2021 VarnamProject. All rights reserved.
+//
+
+import Foundation
+
+struct VarnamException: Error {
+    let message: String
+
+    init(_ message: String) {
+        self.message = message
+    }
+
+    public var localizedDescription: String {
+        return message
+    }
+}
+
+public class Varnam {
+    private var varnamHandle: Int32 = 0;
+
+    internal init(_ schemeID: String = "ml") throws {
+        schemeID.withCString {
+            let rc = varnam_init_from_id(UnsafeMutablePointer(mutating: $0), &varnamHandle)
+            try! checkError(rc)
+        }
+    }
+
+    public func getLastError() -> String {
+        return String(cString: varnam_get_last_error(varnamHandle))
+    }
+
+    public func checkError(_ rc: Int32) throws {
+        if (rc != VARNAM_SUCCESS) {
+            throw VarnamException(getLastError())
+        }
+    }
+
+    public func transliterate(_ input: String) -> [String] {
+        var arr: UnsafeMutablePointer<varray>? = varray_init()
+        let cInput = (input as NSString).utf8String
+        varnam_transliterate(
+            varnamHandle,
+            1,
+            UnsafeMutablePointer(mutating: cInput),
+            &arr
+        )
+
+        var results = [String]()
+        for i in (0..<varray_length(arr)) {
+            let sug = varray_get(arr, i).assumingMemoryBound(to: Suggestion.self
+            )
+            let word = String(cString: sug.pointee.Word)
+            results.append(word)
+        }
+        return results
+    }
+}

GoVarnam/VarnamIME-Bridging-Header.h

@@ -0,0 +1,5 @@
+//
+//  Use this file to import your target's public headers that you would like to expose to Swift.
+//
+
+#include "govarnam/libgovarnam.h"

GoVarnam/build_govarnam.sh

@@ -0,0 +1,4 @@
+cd govarnam
+make library-mac-universal
+install_name_tool -id @executable_path/../Frameworks/libgovarnam.dylib libgovarnam.dylib || exit 1
+cp ./libgovarnam.dylib ../

Input Source/AppDelegate.swift

@@ -53,7 +53,10 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         }
         Logger.log.debug("Initialized IMK Server: \(server.bundle().bundleIdentifier ?? "nil")")
         self.server = server
-        candidatesWindow = IMKCandidates(server: server, panelType: kIMKSingleRowSteppingCandidatePanel)
+
+        // Panel type is the orientation. Default: Vertical
+        // Use kIMKSingleRowSteppingCandidatePanel for horizontal
+        candidatesWindow = IMKCandidates(server: server, panelType: kIMKSingleColumnScrollingCandidatePanel)
         candidatesWindow.setAttributes([IMKCandidatesSendServerKeyEventFirst: NSNumber(booleanLiteral: true)])
     }
 

Input Source/ClientManager.swift

@@ -8,16 +8,16 @@
  */
 
 import InputMethodKit
-import LipikaEngine_OSX
 
 class ClientManager: CustomStringConvertible {
     private let notFoundRange = NSMakeRange(NSNotFound, NSNotFound)
     private let config = VarnamConfig()
     private let client: IMKTextInput
-    // This is the position of the cursor within the marked text
-    public var markedCursorLocation: Int? = nil
+
     private var candidatesWindow: IMKCandidates { return (NSApp.delegate as! AppDelegate).candidatesWindow }
     private (set) var candidates = autoreleasepool { return [String]() }
+    private var tableCursorPos = 0 // Candidates table cursor position
+
     // Cache, otherwise clients quitting can sometimes SEGFAULT us
     private var _description: String
     var description: String {
@@ -31,101 +31,76 @@ class ClientManager: CustomStringConvertible {
 
     init?(client: IMKTextInput) {
         guard let bundleId = client.bundleIdentifier(), let clientId = client.uniqueClientIdentifierString() else {
-            Logger.log.warning("bundleIdentifier: \(client.bundleIdentifier() ?? "nil") or uniqueClientIdentifierString: \(client.uniqueClientIdentifierString() ?? "nil") - failing ClientManager.init()")
+            Log.warning("bundleIdentifier: \(client.bundleIdentifier() ?? "nil") or uniqueClientIdentifierString: \(client.uniqueClientIdentifierString() ?? "nil") - failing ClientManager.init()")
             return nil
         }
-        Logger.log.debug("Initializing client: \(bundleId) with Id: \(clientId)")
+        Log.debug("Initializing client: \(bundleId) with Id: \(clientId)")
         self.client = client
         if !client.supportsUnicode() {
-            Logger.log.warning("Client: \(bundleId) does not support Unicode!")
+            Log.warning("Client: \(bundleId) does not support Unicode!")
         }
         if !client.supportsProperty(TSMDocumentPropertyTag(kTSMDocumentSupportDocumentAccessPropertyTag)) {
-            Logger.log.warning("Client: \(bundleId) does not support Document Access!")
+            Log.warning("Client: \(bundleId) does not support Document Access!")
         }
         _description = "\(bundleId) with Id: \(clientId)"
     }
 
     func setGlobalCursorLocation(_ location: Int) {
-        Logger.log.debug("Setting global cursor location to: \(location)")
+        Log.debug("Setting global cursor location to: \(location)")
         client.setMarkedText("|", selectionRange: NSMakeRange(0, 0), replacementRange: NSMakeRange(location, 0))
         client.setMarkedText("", selectionRange: NSMakeRange(0, 0), replacementRange: NSMakeRange(location, 0))
     }
 
-    func updateMarkedCursorLocation(_ delta: Int) -> Bool {
-        Logger.log.debug("Cursor moved: \(delta) with selectedRange: \(client.selectedRange()), markedRange: \(client.markedRange()) and cursorPosition: \(markedCursorLocation?.description ?? "nil")")
-        if client.markedRange().length == NSNotFound { return false }
-        let nextPosition = (markedCursorLocation ?? client.markedRange().length) + delta
-        if (0...client.markedRange().length).contains(nextPosition) {
-            Logger.log.debug("Still within markedRange")
-            markedCursorLocation = nextPosition
-            return true
-        }
-        Logger.log.debug("Outside of markedRange")
-        markedCursorLocation = nil
-        return false
+    func updatePreedit(_ text: NSAttributedString, _ cursorPos: Int? = nil) {
+        client.setMarkedText(text, selectionRange: NSMakeRange(cursorPos ?? text.length, 0), replacementRange: notFoundRange)
+    }
+
+    func updateCandidates(_ sugs: [String]) {
+        Log.debug(sugs)
+        // Remove duplicates
+        // For some weird reason, when there are duplicates,
+        // candidate window makes them hidden
+        candidates = NSOrderedSet(array: sugs).array as! [String]
+        updateLookupTable()
+    }
+
+    func updateLookupTable() {
+        tableCursorPos = 0
+        candidatesWindow.update()
+        candidatesWindow.show()
     }
 
-    func showActive(clientText: NSAttributedString, candidateText: String, replacementRange: NSRange? = nil) {
-        Logger.log.debug("Showing clientText: \(clientText) and candidateText: \(candidateText)")
-        client.setMarkedText(clientText, selectionRange: NSMakeRange(markedCursorLocation ?? clientText.length, 0), replacementRange: replacementRange ?? notFoundRange)
-        candidates = [candidateText]
-        if clientText.string.isEmpty {
-            candidatesWindow.hide()
+    // For moving between items of candidate table
+    func tableMoveEvent(_ event: NSEvent) {
+        if event.keyCode == kVK_UpArrow && tableCursorPos > 0 {
+            // TODO allow moving to the end
+            // This would need a custom candidate window
+            // https://github.com/lennylxx/google-input-tools-macos/blob/main/GoogleInputTools/CandidatesWindow.swift
+            tableCursorPos -= 1
+        } else if event.keyCode == kVK_DownArrow && tableCursorPos < candidates.count - 1 {
+            tableCursorPos += 1
         }
-        else {
-            candidatesWindow.update()
-            if config.showCandidates {
-                candidatesWindow.show()
-            }
+        candidatesWindow.interpretKeyEvents([event])
+    }
+
+    func getCandidate() -> String? {
+        if candidates.count == 0 {
+            return nil
+        } else {
+            return candidates[tableCursorPos]
         }
     }
 
     func finalize(_ output: String) {
-        Logger.log.debug("Finalizing with: \(output)")
+        Log.debug("Finalizing with: \(output)")
         client.insertText(output, replacementRange: notFoundRange)
         candidatesWindow.hide()
-        markedCursorLocation = nil
     }
 
     func clear() {
-        Logger.log.debug("Clearing MarkedText and Candidate window")
+        Log.debug("Clearing MarkedText and Candidate window")
         client.setMarkedText("", selectionRange: NSMakeRange(0, 0), replacementRange: notFoundRange)
+        candidates = []
         candidatesWindow.hide()
-        markedCursorLocation = nil
-    }
-
-    func findWord(at current: Int) -> NSRange? {
-        let maxLength = client.length()
-        var exponent = 2
-        var wordStart = -1, wordEnd = -1
-        Logger.log.debug("Finding word at: \(current) with max: \(maxLength)")
-        repeat {
-            let low = wordStart == -1 ? max(current - 2 << exponent, 0): wordStart
-            let high = wordEnd == -1 ? min(current + 2 << exponent, maxLength): wordEnd
-            Logger.log.debug("Looking for word between \(low) and \(high)")
-            var real = NSRange()
-            guard let text = client.string(from: NSMakeRange(low, high - low), actualRange: &real) else { return nil }
-            Logger.log.debug("Looking for word in text: \(text)")
-            if wordStart == -1, let startOffset = text.unicodeScalars[text.unicodeScalars.startIndex..<text.unicodeScalars.index(text.unicodeScalars.startIndex, offsetBy: current - real.location)].reversed().firstIndex(where: { CharacterSet.whitespacesAndNewlines.contains($0) })?.base.utf16Offset(in: text) {
-                wordStart = real.location + startOffset
-                Logger.log.debug("Found wordStart: \(wordStart)")
-            }
-            if wordEnd == -1, let endOffset = text.unicodeScalars[text.unicodeScalars.index(text.unicodeScalars.startIndex, offsetBy: current - real.location)..<text.unicodeScalars.endIndex].firstIndex(where: { CharacterSet.whitespacesAndNewlines.contains($0) })?.utf16Offset(in: text) {
-                wordEnd = real.location + endOffset
-                Logger.log.debug("Found wordEnd: \(wordEnd)")
-            }
-            exponent += 1
-            if wordStart == -1, low == 0 {
-                wordStart = low
-                Logger.log.debug("Starting word at beginning of document")
-            }
-            if wordEnd == -1, high == maxLength {
-                wordEnd = high
-                Logger.log.debug("Ending word at end of document")
-            }
-        }
-        while(wordStart == -1 || wordEnd == -1)
-        Logger.log.debug("Found word between \(wordStart) and \(wordEnd)")
-        return NSMakeRange(wordStart, wordEnd - wordStart)
     }
 }