[demo] Wrote linkable label widget

Author: mta452

demo/src/main/java/com/mta/tehreer/demo/LinkableLabel.java

@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2019 Muhammad Tayyab Akram
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.mta.tehreer.demo;
+
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.net.Uri;
+import android.text.Spanned;
+import android.text.style.URLSpan;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+
+import androidx.annotation.Nullable;
+
+import com.mta.tehreer.layout.ComposedFrame;
+import com.mta.tehreer.widget.TLabel;
+
+public class LinkableLabel extends TLabel {
+    private Paint mPaint = new Paint();
+
+    private URLSpan mActiveLinkSpan;
+    private Path mActiveLinkPath;
+
+    public LinkableLabel(Context context) {
+        super(context);
+        setup();
+    }
+
+    public LinkableLabel(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        setup();
+    }
+
+    public LinkableLabel(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        setup();
+    }
+
+    private void setup() {
+        mPaint.setStyle(Paint.Style.FILL);
+        mPaint.setColor(0xFFCCCCEE);
+    }
+
+    private URLSpan urlSpanAtIndex(int charIndex) {
+        Spanned spanned = getSpanned();
+        ComposedFrame composedFrame = getComposedFrame();
+
+        if (spanned == null || composedFrame == null) {
+            return null;
+        }
+        if (charIndex < composedFrame.getCharStart() || charIndex >= composedFrame.getCharEnd()) {
+            return null;
+        }
+
+        URLSpan[] spans = spanned.getSpans(charIndex, charIndex, URLSpan.class);
+        if (spans != null && spans.length > 0) {
+            return spans[0];
+        }
+
+        return null;
+    }
+
+    private URLSpan urlSpanAtPoint(float x, float y) {
+        return urlSpanAtIndex(hitTestPosition(x, y));
+    }
+
+    private void refreshActiveLink() {
+        Spanned spanned = getSpanned();
+        ComposedFrame composedFrame = getComposedFrame();
+
+        if (spanned != null && composedFrame != null && mActiveLinkSpan != null) {
+            int spanStart = spanned.getSpanStart(mActiveLinkSpan);
+            int spanEnd = spanned.getSpanEnd(mActiveLinkSpan);
+
+            mActiveLinkPath = composedFrame.generateSelectionPath(spanStart, spanEnd);
+            mActiveLinkPath.offset(composedFrame.getOriginX(), composedFrame.getOriginY());
+        } else {
+            mActiveLinkPath = null;
+        }
+
+        invalidate();
+    }
+
+    private void clearActiveLink() {
+        mActiveLinkSpan = null;
+        refreshActiveLink();
+    }
+
+    private void openActiveLink() {
+        Uri uri = Uri.parse(mActiveLinkSpan.getURL());
+        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
+        Context context = getContext();
+        context.startActivity(intent);
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        if (mActiveLinkPath != null) {
+            canvas.drawPath(mActiveLinkPath, mPaint);
+        }
+
+        super.onDraw(canvas);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        int action = event.getActionMasked();
+        switch (action) {
+        case MotionEvent.ACTION_DOWN:
+            mActiveLinkSpan = urlSpanAtPoint(event.getX(), event.getY());
+            if (mActiveLinkSpan != null) {
+                refreshActiveLink();
+                return true;
+            }
+            break;
+
+        case MotionEvent.ACTION_MOVE:
+            if (mActiveLinkSpan != null) {
+                URLSpan pointedLinkSpan = urlSpanAtPoint(event.getX(), event.getY());
+                if (pointedLinkSpan != mActiveLinkSpan) {
+                    clearActiveLink();
+                }
+
+                return true;
+            }
+            break;
+
+        case MotionEvent.ACTION_UP:
+            if (mActiveLinkSpan != null) {
+                performClick();
+                openActiveLink();
+                clearActiveLink();
+                return true;
+            }
+            break;
+
+        case MotionEvent.ACTION_CANCEL:
+            if (mActiveLinkSpan != null) {
+                clearActiveLink();
+                return true;
+            }
+            break;
+        }
+
+        return super.onTouchEvent(event);
+    }
+}