Adds a tiny tooltop for shift-left/right selections.

McBopomofo.xcodeproj/project.pbxproj

@@ -42,6 +42,7 @@
 		D427A9C125ED28CC005D43E0 /* OpenCCBridge.swift in Sources */ = {isa = PBXBuildFile; fileRef = D427A9C025ED28CC005D43E0 /* OpenCCBridge.swift */; };
 		D427F76A278C9E29004A2160 /* CandidateUI in Frameworks */ = {isa = PBXBuildFile; productRef = D427F769278C9E29004A2160 /* CandidateUI */; };
 		D427F76C278CA2B0004A2160 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = D427F76B278CA1BA004A2160 /* AppDelegate.swift */; };
+		D427F7A927905E90004A2160 /* TooltipUI in Frameworks */ = {isa = PBXBuildFile; productRef = D427F7A827905E90004A2160 /* TooltipUI */; };
 		D47F7DCE278BFB57002F9DD7 /* PreferencesWindowController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D47F7DCD278BFB57002F9DD7 /* PreferencesWindowController.swift */; };
 		D47F7DD0278C0897002F9DD7 /* NonModalAlertWindowController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D47F7DCF278C0897002F9DD7 /* NonModalAlertWindowController.swift */; };
 		D47F7DD3278C1263002F9DD7 /* UserOverrideModel.cpp in Sources */ = {isa = PBXBuildFile; fileRef = D47F7DD2278C1263002F9DD7 /* UserOverrideModel.cpp */; };
@@ -168,6 +169,7 @@
 		D427A9C025ED28CC005D43E0 /* OpenCCBridge.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OpenCCBridge.swift; sourceTree = "<group>"; };
 		D427F768278C9D0D004A2160 /* CandidateUI */ = {isa = PBXFileReference; lastKnownFileType = wrapper; name = CandidateUI; path = Packages/CandidateUI; sourceTree = "<group>"; };
 		D427F76B278CA1BA004A2160 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
+		D427F7A727905E43004A2160 /* TooltipUI */ = {isa = PBXFileReference; lastKnownFileType = wrapper; name = TooltipUI; path = Packages/TooltipUI; sourceTree = "<group>"; };
 		D47F7DCD278BFB57002F9DD7 /* PreferencesWindowController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesWindowController.swift; sourceTree = "<group>"; };
 		D47F7DCF278C0897002F9DD7 /* NonModalAlertWindowController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NonModalAlertWindowController.swift; sourceTree = "<group>"; };
 		D47F7DD1278C1263002F9DD7 /* UserOverrideModel.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = UserOverrideModel.h; sourceTree = "<group>"; };
@@ -182,6 +184,7 @@
 			files = (
 				6A38BC2815FC158A00A8A51F /* InputMethodKit.framework in Frameworks */,
 				D48550A325EBE689006A204C /* OpenCC in Frameworks */,
+				D427F7A927905E90004A2160 /* TooltipUI in Frameworks */,
 				D427F76A278C9E29004A2160 /* CandidateUI in Frameworks */,
 				6A0D4EA715FC0D2D00ABF4B3 /* Cocoa.framework in Frameworks */,
 			);
@@ -393,6 +396,7 @@
 			isa = PBXGroup;
 			children = (
 				D427F768278C9D0D004A2160 /* CandidateUI */,
+				D427F7A727905E43004A2160 /* TooltipUI */,
 			);
 			name = Packages;
 			sourceTree = "<group>";
@@ -434,6 +438,7 @@
 			packageProductDependencies = (
 				D48550A225EBE689006A204C /* OpenCC */,
 				D427F769278C9E29004A2160 /* CandidateUI */,
+				D427F7A827905E90004A2160 /* TooltipUI */,
 			);
 			productName = McBopomofo;
 			productReference = 6A0D4EA215FC0D2D00ABF4B3 /* McBopomofo.app */;
@@ -1059,6 +1064,10 @@
 			isa = XCSwiftPackageProductDependency;
 			productName = CandidateUI;
 		};
+		D427F7A827905E90004A2160 /* TooltipUI */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = TooltipUI;
+		};
 		D48550A225EBE689006A204C /* OpenCC */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = D48550A125EBE689006A204C /* XCRemoteSwiftPackageReference "SwiftyOpenCC" */;

Packages/CandidateUI/Sources/CandidateUI/HorizontalCandidateController.swift

@@ -203,7 +203,7 @@ public class HorizontalCandidateController: CandidateController {
         var contentRect = NSRect(x: 128.0, y: 128.0, width: 0.0, height: 0.0)
         let styleMask: NSWindow.StyleMask = [.borderless, .nonactivatingPanel]
         let panel = NSPanel(contentRect: contentRect, styleMask: styleMask, backing: .buffered, defer: false)
-        panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel))
+        panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel) + 1)
         panel.hasShadow = true
 
         contentRect.origin = NSPoint.zero

Packages/TooltipUI/.gitignore

@@ -0,0 +1,7 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
+xcuserdata/
+DerivedData/
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata

Packages/TooltipUI/Package.swift

@@ -0,0 +1,25 @@
+// swift-tools-version:5.5
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "TooltipUI",
+    products: [
+        // Products define the executables and libraries a package produces, and make them visible to other packages.
+        .library(
+            name: "TooltipUI",
+            targets: ["TooltipUI"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages this package depends on.
+        .target(
+            name: "TooltipUI",
+            dependencies: []),
+    ]
+)

Packages/TooltipUI/README.md

@@ -0,0 +1,3 @@
+# TooltipUI
+
+A description of this package.

Packages/TooltipUI/Sources/TooltipUI/TooltipController.swift

@@ -0,0 +1,65 @@
+import Cocoa
+
+public class TooltipController: NSWindowController {
+    let backgroundColor =  NSColor(calibratedHue: 0.16, saturation: 0.22, brightness: 0.97, alpha: 1.0)
+    var messageTextField: NSTextField
+    var tooltip: String  = "" {
+        didSet {
+            messageTextField.stringValue = tooltip
+            adjustSize()
+        }
+    }
+
+    public init() {
+        let contentRect = NSRect(x: 128.0, y: 128.0, width: 300.0, height: 20.0)
+        let styleMask: NSWindow.StyleMask = [.borderless, .nonactivatingPanel]
+        let panel = NSPanel(contentRect: contentRect, styleMask: styleMask, backing: .buffered, defer: false)
+        panel.level = NSWindow.Level(Int(kCGPopUpMenuWindowLevel))
+        panel.hasShadow = true
+
+        messageTextField = NSTextField()
+        messageTextField.isEditable = false
+        messageTextField.isSelectable = false
+        messageTextField.isBezeled = false
+        messageTextField.textColor = .black
+        messageTextField.drawsBackground = true
+        messageTextField.backgroundColor = backgroundColor
+        messageTextField.font = .systemFont(ofSize: NSFont.systemFontSize(for: .small))
+        panel.contentView?.addSubview(messageTextField)
+
+        super.init(window: panel)
+    }
+
+    public required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    @objc(showTooltip:atPoint:)
+    public func show(tooltip: String, at point: NSPoint) {
+        self.tooltip = tooltip
+        window?.orderFront(nil)
+        set(windowLocation: point)
+    }
+
+    @objc
+    public func hide() {
+        window?.orderOut(nil)
+    }
+
+    private func set(windowLocation location: NSPoint) {
+        var newPoint = location
+        if location.y > 5 {
+            newPoint.y -= 5
+        }
+        window?.setFrameTopLeftPoint(newPoint)
+    }
+
+    private func adjustSize() {
+        let attrString = messageTextField.attributedStringValue;
+        var rect = attrString.boundingRect(with: NSSize(width: 1600.0, height: 1600.0), options: .usesLineFragmentOrigin)
+        rect.size.width += 10
+        messageTextField.frame = rect
+        window?.setFrame(rect, display: true)
+    }
+
+}

Source/InputMethodController.mm

@@ -42,6 +42,7 @@
 #import "McBopomofo-Swift.h"
 
 @import CandidateUI;
+@import TooltipUI;
 @import OpenCC;
 
 // C++ namespace usages
@@ -489,6 +490,7 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
         // i.e. the client app needs to take care of where to put ths composing buffer
         [client setMarkedText:attrString selectionRange:NSMakeRange((NSInteger)_builder->markerCursorIndex(), 0) replacementRange:NSMakeRange(NSNotFound, NSNotFound)];
         _latestReadingCursor = (NSInteger)_builder->markerCursorIndex();
+        [self _showCurrentMarkedTextTooltipWithClient:client];
     }
     else {
         // we must use NSAttributedString so that the cursor is visible --
@@ -501,6 +503,7 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
         // i.e. the client app needs to take care of where to put ths composing buffer
         [client setMarkedText:attrString selectionRange:NSMakeRange(cursorIndex, 0) replacementRange:NSMakeRange(NSNotFound, NSNotFound)];
         _latestReadingCursor = cursorIndex;
+        [self _hideTooltip];
     }
 }
 
@@ -606,47 +609,7 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
     return layout;
 }
 
-- (NSString *)_currentMarkedText
+- (McBpomofoEmacsKey)_detectEmacsKeyFromCharCode:(UniChar)charCode modifiers:(NSUInteger)flags
-{
-    if (_builder->markerCursorIndex() < 0) {
-        return @"";
-    }
-    if (!_bpmfReadingBuffer->isEmpty()) {
-        return @"";
-    }
-
-    size_t begin = min(_builder->markerCursorIndex(), _builder->cursorIndex());
-    size_t end = max(_builder->markerCursorIndex(), _builder->cursorIndex());
-    // A phrase should contian at least two characters.
-    if (end - begin < 2) {
-        return @"";
-    }
-
-    NSRange range = NSMakeRange((NSInteger)begin, (NSInteger)(end - begin));
-    NSString *reading = [_composingBuffer substringWithRange:range];
-    NSMutableString *string = [[NSMutableString alloc] init];
-    [string appendString:reading];
-    [string appendString:@" "];
-    NSMutableArray *readingsArray = [[NSMutableArray alloc] init];
-    vector<std::string> v = _builder->readingsAtRange(begin, end);
-    for(vector<std::string>::iterator it_i=v.begin(); it_i!=v.end(); ++it_i) {
-        [readingsArray addObject:[NSString stringWithUTF8String:it_i->c_str()]];
-    }
-    [string appendString:[readingsArray componentsJoinedByString:@"-"]];
-    return string;
-}
-
-- (BOOL)_writeUserPhrase
-{
-    NSString *currentMarkedPhrase = [self _currentMarkedText];
-    if (![currentMarkedPhrase length]) {
-        return NO;
-    }
-
-    return [LanguageModelManager writeUserPhrase:currentMarkedPhrase];
-}
-
-- (McBpomofoEmacsKey)detectEmacsKeyFromCharCode:(UniChar)charCode modifiers:(NSUInteger)flags
 {
     if (flags & NSControlKeyMask) {
         char c = charCode + 'a' - 1;
@@ -698,7 +661,7 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
     // get the unicode character code
     UniChar charCode = [inputText length] ? [inputText characterAtIndex:0] : 0;
 
-    McBpomofoEmacsKey emacsKey = [self detectEmacsKeyFromCharCode:charCode modifiers:flags];
+    McBpomofoEmacsKey emacsKey = [self _detectEmacsKeyFromCharCode:charCode modifiers:flags];
 
     if ([[client bundleIdentifier] isEqualToString:@"com.apple.Terminal"] && [NSStringFromClass([client class]) isEqualToString:@"IPMDServerClientWrapper"]) {
         // special handling for com.apple.Terminal
@@ -1400,24 +1363,30 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
 + (VTHorizontalCandidateController *)horizontalCandidateController
 {
     static VTHorizontalCandidateController *instance = nil;
-    @synchronized(self) {
+    static dispatch_once_t onceToken;
-        if (!instance) {
+    dispatch_once(&onceToken, ^{
-            instance = [[VTHorizontalCandidateController alloc] init];
+        instance = [[VTHorizontalCandidateController alloc] init];
-        }
+    });
-    }
-
     return instance;
 }
 
 + (VTVerticalCandidateController *)verticalCandidateController
 {
     static VTVerticalCandidateController *instance = nil;
-    @synchronized(self) {
+    static dispatch_once_t onceToken;
-        if (!instance) {
+    dispatch_once(&onceToken, ^{
-            instance = [[VTVerticalCandidateController alloc] init];
+        instance = [[VTVerticalCandidateController alloc] init];
-        }
+    });
-    }
+    return instance;
+}
 
++ (TooltipController *)tooltipController
+{
+    static TooltipController *instance = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        instance = [[TooltipController alloc] init];
+    });
     return instance;
 }
 
@@ -1541,6 +1510,113 @@ NS_INLINE size_t max(size_t a, size_t b) { return a > b ? a : b; }
     gCurrentCandidateController.visible = YES;
 }
 
+#pragma mark - User phrases
+
+- (NSString *)_currentMarkedText
+{
+    if (_builder->markerCursorIndex() < 0) {
+        return @"";
+    }
+    if (!_bpmfReadingBuffer->isEmpty()) {
+        return @"";
+    }
+
+    size_t begin = min(_builder->markerCursorIndex(), _builder->cursorIndex());
+    size_t end = max(_builder->markerCursorIndex(), _builder->cursorIndex());
+    // A phrase should contian at least two characters.
+    if (end - begin < 1) {
+        return @"";
+    }
+
+    NSRange range = NSMakeRange((NSInteger)begin, (NSInteger)(end - begin));
+    NSString *selectedText = [_composingBuffer substringWithRange:range];
+    return selectedText;
+}
+
+- (NSString *)_currentMarkedTextAndReadings
+{
+    if (_builder->markerCursorIndex() < 0) {
+        return @"";
+    }
+    if (!_bpmfReadingBuffer->isEmpty()) {
+        return @"";
+    }
+
+    size_t begin = min(_builder->markerCursorIndex(), _builder->cursorIndex());
+    size_t end = max(_builder->markerCursorIndex(), _builder->cursorIndex());
+    // A phrase should contian at least two characters.
+    if (end - begin < 2) {
+        return @"";
+    }
+
+    NSRange range = NSMakeRange((NSInteger)begin, (NSInteger)(end - begin));
+    NSString *selectedText = [_composingBuffer substringWithRange:range];
+    NSMutableString *string = [[NSMutableString alloc] init];
+    [string appendString:selectedText];
+    [string appendString:@" "];
+    NSMutableArray *readingsArray = [[NSMutableArray alloc] init];
+    vector<std::string> v = _builder->readingsAtRange(begin, end);
+    for(vector<std::string>::iterator it_i=v.begin(); it_i!=v.end(); ++it_i) {
+        [readingsArray addObject:[NSString stringWithUTF8String:it_i->c_str()]];
+    }
+    [string appendString:[readingsArray componentsJoinedByString:@"-"]];
+    return string;
+}
+
+- (BOOL)_writeUserPhrase
+{
+    NSString *currentMarkedPhrase = [self _currentMarkedTextAndReadings];
+    if (![currentMarkedPhrase length]) {
+        return NO;
+    }
+
+    return [LanguageModelManager writeUserPhrase:currentMarkedPhrase];
+}
+
+- (void)_showCurrentMarkedTextTooltipWithClient:(id)client
+{
+    NSString *text = [self _currentMarkedText];
+    NSInteger length = text.length;
+    if (!length) {
+        [self _hideTooltip];
+    }
+    else if (length == 1) {
+        NSString *messsage = [NSString stringWithFormat:NSLocalizedString(@"You are now selecting \"%@\". You can add a phrase with two or more characters.", @""), text];
+        [self _showTooltip:messsage client:client];
+    }
+    else {
+        NSString *messsage = [NSString stringWithFormat:NSLocalizedString(@"You are now selecting \"%@\". Press enter to add a new phrase.", @""), text];
+        [self _showTooltip:messsage client:client];
+    }
+}
+
+- (void)_showTooltip:(NSString *)tooltip client:(id)client
+{
+    NSRect lineHeightRect = NSMakeRect(0.0, 0.0, 16.0, 16.0);
+
+    NSInteger cursor = _latestReadingCursor;
+    if (cursor == [_composingBuffer length] && cursor != 0) {
+        cursor--;
+    }
+
+    // some apps (e.g. Twitter for Mac's search bar) handle this call incorrectly, hence the try-catch
+    @try {
+        [client attributesForCharacterIndex:cursor lineHeightRectangle:&lineHeightRect];
+    }
+    @catch (NSException *exception) {
+        NSLog(@"%@", exception);
+    }
+
+    [[McBopomofoInputMethodController tooltipController] showTooltip:tooltip atPoint:lineHeightRect.origin];
+}
+
+- (void)_hideTooltip
+{
+    if ([McBopomofoInputMethodController tooltipController].window.isVisible) {
+        [[McBopomofoInputMethodController tooltipController] hide];
+    }
+}
+
 #pragma mark - Misc menu items
 
 - (void)showPreferences:(id)sender