feat: TappableSpan support (#8256)

* feat(android): clickable span

Initial support for clickable span on Android

* test: clickable-span test page

* remove console.log

* use _emit instead of notify

* rename clickable to tappable in Span

* updated NativeScript.api.md

* chore: fixing tslint errors

* chore: fixed witespacing

* moved and improved test page

* feat: tappable span iOS implementation

Co-authored-by: Eduardo Speroni <edusperoni@gmail.com>

api-reports/NativeScript.api.md

@@ -1936,9 +1936,13 @@ export class Span extends ViewBase {
 
     public fontWeight: FontWeight;
 
+    public static linkTapEvent: string;
+
     // (undocumented)
     _setTextInternal(value: string): void;
 
+    public readonly tappable: boolean;
+
     public text: string;
 
     public textDecoration: TextDecoration;

e2e/ui-tests-app/app/button/main-page.ts

@@ -18,6 +18,7 @@ export function loadExamples() {
     examples.set("issue-4287", "button/issue-4287-page");
     examples.set("issue-4385", "button/issue-4385-page");
     examples.set("highlight-4740", "button/highlight-4740/highlight-4740-page");
+    examples.set("tappable-span", "button/tappable-span-page");
 
     return examples;
 }

nativescript-core/ui/text-base/span.d.ts

@@ -50,6 +50,15 @@ export class Span extends ViewBase {
      * Gets or sets the text for the span.
      */
     public text: string;
+    /**
+     * String value used when hooking to linkTap event.
+     */
+    public static linkTapEvent: string;
+
+    /**
+     * Gets if the span is tappable or not.
+     */
+    public readonly tappable: boolean;
 
     //@private
     /**

nativescript-core/ui/text-base/span.ts

@@ -2,10 +2,12 @@
 import { Span as SpanDefinition } from "./span";
 import { ViewBase } from "../core/view";
 import { FontStyle, FontWeight, } from "../styling/font";
-import { TextDecoration } from "../text-base";
+import { TextDecoration, EventData } from "../text-base";
 
 export class Span extends ViewBase implements SpanDefinition {
+    static linkTapEvent = "linkTap";
     private _text: string;
+    private _tappable: boolean = false;
 
     get fontFamily(): string {
         return this.style.fontFamily;
@@ -68,7 +70,28 @@ export class Span extends ViewBase implements SpanDefinition {
         }
     }
 
+    get tappable(): boolean {
+        return this._tappable;
+    }
+
+    addEventListener(arg: string, callback: (data: EventData) => void, thisArg?: any) {
+        super.addEventListener(arg, callback, thisArg);
+        this._setTappable(this.hasListeners(Span.linkTapEvent));
+    }
+
+    removeEventListener(arg: string, callback?: any, thisArg?: any) {
+        super.removeEventListener(arg, callback, thisArg);
+        this._setTappable(this.hasListeners(Span.linkTapEvent));
+    }
+
     _setTextInternal(value: string): void {
         this._text = value;
     }
+
+    private _setTappable(value: boolean): void {
+        if (this._tappable !== value) {
+            this._tappable = value;
+            this.notifyPropertyChange("tappable", value);
+        }
+    }
 }

nativescript-core/ui/text-base/text-base.android.ts

@@ -51,6 +51,42 @@ function initializeTextTransformation(): void {
     TextTransformation = TextTransformationImpl;
 }
 
+interface ClickableSpan {
+    new (owner: Span): android.text.style.ClickableSpan;
+}
+
+let ClickableSpan: ClickableSpan;
+
+function initializeClickableSpan(): void {
+    if (ClickableSpan) {
+        return;
+    }
+
+    class ClickableSpanImpl extends android.text.style.ClickableSpan {
+        owner: WeakRef<Span>;
+
+        constructor(owner: Span) {
+            super();
+            this.owner = new WeakRef(owner);
+
+            return global.__native(this);
+        }
+        onClick(view: android.view.View): void {
+            const owner = this.owner.get();
+            if (owner) {
+                owner._emit(Span.linkTapEvent);
+            }
+            view.clearFocus();
+            view.invalidate();
+        }
+        updateDrawState(tp: android.text.TextPaint): void {
+            // don't style as link
+        }
+    }
+
+    ClickableSpan = ClickableSpanImpl;
+}
+
 export class TextBase extends TextBaseCommon {
     nativeViewProtected: android.widget.TextView;
     nativeTextViewProtected: android.widget.TextView;
@@ -60,12 +96,15 @@ export class TextBase extends TextBaseCommon {
     private _maxHeight: number;
     private _minLines: number;
     private _maxLines: number;
+    private _tappable: boolean = false;
+    private _defaultMovementMethod: android.text.method.MovementMethod;
 
     public initNativeView(): void {
         super.initNativeView();
         initializeTextTransformation();
         const nativeView = this.nativeTextViewProtected;
         this._defaultTransformationMethod = nativeView.getTransformationMethod();
+        this._defaultMovementMethod = this.nativeView.getMovementMethod();
         this._minHeight = nativeView.getMinHeight();
         this._maxHeight = nativeView.getMaxHeight();
         this._minLines = nativeView.getMinLines();
@@ -112,6 +151,8 @@ export class TextBase extends TextBaseCommon {
             return;
         }
 
+        this._setTappableState(false);
+
         this._setNativeText(reset);
     }
 
@@ -131,6 +172,7 @@ export class TextBase extends TextBaseCommon {
 
         const spannableStringBuilder = createSpannableStringBuilder(value);
         nativeView.setText(<any>spannableStringBuilder);
+        this._setTappableState(isStringTappable(value));
 
         textProperty.nativeValueChange(this, (value === null || value === undefined) ? "" : value.toString());
 
@@ -315,6 +357,19 @@ export class TextBase extends TextBaseCommon {
 
         this.nativeTextViewProtected.setText(<any>transformedText);
     }
+
+    _setTappableState(tappable: boolean) {
+        if (this._tappable !== tappable) {
+            this._tappable = tappable;
+            if (this._tappable) {
+                this.nativeViewProtected.setMovementMethod(android.text.method.LinkMovementMethod.getInstance());
+                this.nativeViewProtected.setHighlightColor(null);
+            }
+            else {
+                this.nativeViewProtected.setMovementMethod(this._defaultMovementMethod);
+            }
+        }
+    }
 }
 
 function getCapitalizedString(str: string): string {
@@ -346,6 +401,20 @@ export function getTransformedText(text: string, textTransform: TextTransform):
     }
 }
 
+function isStringTappable(formattedString: FormattedString) {
+    if (!formattedString) {
+        return false;
+    }
+    for (let i = 0, length = formattedString.spans.length; i < length; i++) {
+        const span = formattedString.spans.getItem(i);
+        if (span.tappable) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 function createSpannableStringBuilder(formattedString: FormattedString): android.text.SpannableStringBuilder {
     if (!formattedString || !formattedString.parent) {
         return null;
@@ -444,6 +513,12 @@ function setSpanModifiers(ssb: android.text.SpannableStringBuilder, span: Span,
         }
     }
 
+    const tappable = span.tappable;
+    if (tappable) {
+        initializeClickableSpan();
+        ssb.setSpan(new ClickableSpan(span), start, end, android.text.Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+    }
+
     // TODO: Implement letterSpacing for Span here.
     // const letterSpacing = formattedString.parent.style.letterSpacing;
     // if (letterSpacing > 0) {

nativescript-core/ui/text-base/text-base.ios.ts

@@ -15,10 +15,101 @@ export * from "./text-base-common";
 
 const majorVersion = ios.MajorVersion;
 
+class UILabelClickHandlerImpl extends NSObject {
+    private _owner: WeakRef<TextBase>;
+
+    public static initWithOwner(owner: WeakRef<TextBase>): UILabelClickHandlerImpl {
+        let handler = <UILabelClickHandlerImpl>UILabelClickHandlerImpl.new();
+        handler._owner = owner;
+
+        return handler;
+    }
+
+    public linkTap(tapGesture: UITapGestureRecognizer) {
+        let owner = this._owner.get();
+        if (owner) {
+            // https://stackoverflow.com/a/35789589
+            let label = <UILabel>owner.nativeTextViewProtected;
+            let layoutManager = NSLayoutManager.alloc().init();
+            let textContainer = NSTextContainer.alloc().initWithSize(CGSizeZero);
+            let textStorage = NSTextStorage.alloc().initWithAttributedString(owner.nativeTextViewProtected["attributedText"]);
+
+            layoutManager.addTextContainer(textContainer);
+            textStorage.addLayoutManager(layoutManager);
+
+            textContainer.lineFragmentPadding = 0;
+            textContainer.lineBreakMode = label.lineBreakMode;
+            textContainer.maximumNumberOfLines = label.numberOfLines;
+            let labelSize = label.bounds.size;
+            textContainer.size = labelSize;
+
+            let locationOfTouchInLabel = tapGesture.locationInView(label);
+            let textBoundingBox = layoutManager.usedRectForTextContainer(textContainer);
+
+            let textContainerOffset = CGPointMake((labelSize.width - textBoundingBox.size.width) * 0.5 - textBoundingBox.origin.x,
+                    (labelSize.height - textBoundingBox.size.height) * 0.5 - textBoundingBox.origin.y);
+
+            let locationOfTouchInTextContainer = CGPointMake(locationOfTouchInLabel.x - textContainerOffset.x,
+                    locationOfTouchInLabel.y - textContainerOffset.y);
+
+            let indexOfCharacter = layoutManager.characterIndexForPointInTextContainerFractionOfDistanceBetweenInsertionPoints(
+                    locationOfTouchInTextContainer, textContainer, null);
+
+            let span: Span = null;
+            // try to find the corresponding span using the spanRanges
+            for (let i = 0; i < owner._spanRanges.length; i++) {
+                let range = owner._spanRanges[i];
+                if ((range.location <= indexOfCharacter) && (range.location + range.length) > indexOfCharacter) {
+                    if (owner.formattedText && owner.formattedText.spans.length > i) {
+                        span = owner.formattedText.spans.getItem(i);
+                    }
+                    break;
+                }
+            }
+
+            if (span && span.tappable) {
+                // if the span is found and tappable emit the linkTap event
+                span._emit(Span.linkTapEvent);
+            }
+        }
+    }
+
+    public static ObjCExposedMethods = {
+        "linkTap": { returns: interop.types.void, params: [interop.types.id] }
+    };
+}
+
 export class TextBase extends TextBaseCommon {
 
     public nativeViewProtected: UITextField | UITextView | UILabel | UIButton;
     public nativeTextViewProtected: UITextField | UITextView | UILabel | UIButton;
+    private _tappable: boolean = false;
+    private _tapGestureRecognizer: UITapGestureRecognizer;
+    public _spanRanges: NSRange[];
+
+    public initNativeView(): void {
+        super.initNativeView();
+        this._setTappableState(false);
+    }
+
+    _setTappableState(tappable: boolean) {
+        if (this._tappable !== tappable) {
+            this._tappable = tappable;
+            if (this._tappable) {
+                const tapHandler = UILabelClickHandlerImpl.initWithOwner(new WeakRef(this));
+                // associate handler with menuItem or it will get collected by JSC.
+                (<any>this).handler = tapHandler;
+
+                this._tapGestureRecognizer = UITapGestureRecognizer.alloc().initWithTargetAction(tapHandler, "linkTap");
+                this.nativeViewProtected.userInteractionEnabled = true;
+                this.nativeViewProtected.addGestureRecognizer(this._tapGestureRecognizer);
+            }
+            else {
+                this.nativeViewProtected.userInteractionEnabled = false;
+                this.nativeViewProtected.removeGestureRecognizer(this._tapGestureRecognizer);
+            }
+        }
+    }
 
     [textProperty.getDefault](): number | symbol {
         return resetSymbol;
@@ -35,6 +126,7 @@ export class TextBase extends TextBaseCommon {
 
     [formattedTextProperty.setNative](value: FormattedString) {
         this._setNativeText();
+        this._setTappableState(isStringTappable(value));
         textProperty.nativeValueChange(this, !value ? "" : value.toString());
         this._requestLayoutOnTextChanged();
     }
@@ -253,6 +345,7 @@ export class TextBase extends TextBaseCommon {
 
     createNSMutableAttributedString(formattedString: FormattedString): NSMutableAttributedString {
         let mas = NSMutableAttributedString.alloc().init();
+        this._spanRanges = [];
         if (formattedString && formattedString.parent) {
             for (let i = 0, spanStart = 0, length = formattedString.spans.length; i < length; i++) {
                 const span = formattedString.spans.getItem(i);
@@ -265,6 +358,7 @@ export class TextBase extends TextBaseCommon {
 
                 const nsAttributedString = this.createMutableStringForSpan(span, spanText);
                 mas.insertAttributedStringAtIndex(nsAttributedString, spanStart);
+                this._spanRanges.push({location: spanStart, length: spanText.length});
                 spanStart += spanText.length;
             }
         }
@@ -349,3 +443,17 @@ export function getTransformedText(text: string, textTransform: TextTransform):
 function NSStringFromNSAttributedString(source: NSAttributedString | string): NSString {
     return NSString.stringWithString(source instanceof NSAttributedString && source.string || <string>source);
 }
+
+function isStringTappable(formattedString: FormattedString) {
+    if (!formattedString) {
+        return false;
+    }
+    for (let i = 0, length = formattedString.spans.length; i < length; i++) {
+        const span = formattedString.spans.getItem(i);
+        if (span.tappable) {
+            return true;
+        }
+    }
+
+    return false;
+}