Add ability to copy hashtags, URLs and timestamps in descriptions on long-press

This commit adds the ability to copy to clipboard hashtags, URLs and timestamps
when long-pressing them.

Some changes in our TextView class related to text setting have been required
and metadata items are now using a NewPipeTextView instead of a standard
TextView.

Six new classes have been added:

- a custom LinkMovementMethod class;
- a custom ClickableSpan class, LongPressClickableSpan, in order to set a long
  press event;
- a class to avoid code duplication in CommentTextOnTouchListener, TouchUtils;
- three implementations of LongPressClickableSpan used when linkifying text:
  - HashtagLongPressClickableSpan for hashtags;
  - TimestampLongPressClickableSpan for timestamps;
  - UrlLongPressClickableSpan for URLs.

app/src/main/java/org/schabi/newpipe/views/LongPressClickableSpan.java

@@ -0,0 +1,12 @@
+package org.schabi.newpipe.views;
+
+import android.text.style.ClickableSpan;
+import android.view.View;
+
+import androidx.annotation.NonNull;
+
+public abstract class LongPressClickableSpan extends ClickableSpan {
+
+    public abstract void onLongClick(@NonNull View view);
+
+}

app/src/main/java/org/schabi/newpipe/views/LongPressLinkMovementMethod.java

@@ -0,0 +1,77 @@
+package org.schabi.newpipe.views;
+
+import static org.schabi.newpipe.util.TouchUtils.getOffsetForHorizontalLine;
+
+import android.os.Handler;
+import android.os.Looper;
+import android.text.Selection;
+import android.text.Spannable;
+import android.text.method.LinkMovementMethod;
+import android.text.method.MovementMethod;
+import android.view.MotionEvent;
+import android.view.ViewConfiguration;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+
+// Class adapted from https://stackoverflow.com/a/31786969
+
+public class LongPressLinkMovementMethod extends LinkMovementMethod {
+
+    private static final int LONG_PRESS_TIME = ViewConfiguration.getLongPressTimeout();
+
+    private static LongPressLinkMovementMethod instance;
+
+    private Handler longClickHandler;
+    private boolean isLongPressed = false;
+
+    @Override
+    public boolean onTouchEvent(@NonNull final TextView widget,
+                                @NonNull final Spannable buffer,
+                                @NonNull final MotionEvent event) {
+        final int action = event.getAction();
+
+        if (action == MotionEvent.ACTION_CANCEL && longClickHandler != null) {
+            longClickHandler.removeCallbacksAndMessages(null);
+        }
+
+        if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_DOWN) {
+            final int offset = getOffsetForHorizontalLine(widget, event);
+            final LongPressClickableSpan[] link = buffer.getSpans(offset, offset,
+                    LongPressClickableSpan.class);
+
+            if (link.length != 0) {
+                if (action == MotionEvent.ACTION_UP) {
+                    if (longClickHandler != null) {
+                        longClickHandler.removeCallbacksAndMessages(null);
+                    }
+                    if (!isLongPressed) {
+                        link[0].onClick(widget);
+                    }
+                    isLongPressed = false;
+                } else {
+                    Selection.setSelection(buffer, buffer.getSpanStart(link[0]),
+                            buffer.getSpanEnd(link[0]));
+                    if (longClickHandler != null) {
+                        longClickHandler.postDelayed(() -> {
+                            link[0].onLongClick(widget);
+                            isLongPressed = true;
+                        }, LONG_PRESS_TIME);
+                    }
+                }
+                return true;
+            }
+        }
+
+        return super.onTouchEvent(widget, buffer, event);
+    }
+
+    public static MovementMethod getInstance() {
+        if (instance == null) {
+            instance = new LongPressLinkMovementMethod();
+            instance.longClickHandler = new Handler(Looper.myLooper());
+        }
+
+        return instance;
+    }
+}

app/src/main/java/org/schabi/newpipe/views/NewPipeEditText.java

@@ -13,9 +13,10 @@ import org.schabi.newpipe.util.external_communication.ShareUtils;
 /**
  * An {@link AppCompatEditText} which uses {@link ShareUtils#shareText(Context, String, String)}
  * when sharing selected text by using the {@code Share} command of the floating actions.
+ *
  * <p>
- * This allows NewPipe to show Android share sheet instead of EMUI share sheet when sharing text
- * from {@link AppCompatEditText} on EMUI devices.
+ * This class allows NewPipe to show Android share sheet instead of EMUI share sheet when sharing
+ * text from {@link AppCompatEditText} on EMUI devices.
  * </p>
  */
 public class NewPipeEditText extends AppCompatEditText {

app/src/main/java/org/schabi/newpipe/views/NewPipeTextView.java

@@ -1,6 +1,7 @@
 package org.schabi.newpipe.views;
 
 import android.content.Context;
+import android.text.method.MovementMethod;
 import android.util.AttributeSet;
 
 import androidx.annotation.NonNull;
@@ -13,9 +14,11 @@ import org.schabi.newpipe.util.external_communication.ShareUtils;
 /**
  * An {@link AppCompatTextView} which uses {@link ShareUtils#shareText(Context, String, String)}
  * when sharing selected text by using the {@code Share} command of the floating actions.
+ *
  * <p>
- * This allows NewPipe to show Android share sheet instead of EMUI share sheet when sharing text
- * from {@link AppCompatTextView} on EMUI devices.
+ * This class allows NewPipe to show Android share sheet instead of EMUI share sheet when sharing
+ * text from {@link AppCompatTextView} on EMUI devices and also to keep movement method set when a
+ * text change occurs, if the text cannot be selected and text links are clickable.
  * </p>
  */
 public class NewPipeTextView extends AppCompatTextView {
@@ -34,6 +37,16 @@ public class NewPipeTextView extends AppCompatTextView {
         super(context, attrs, defStyleAttr);
     }
 
+    @Override
+    public void setText(final CharSequence text, final BufferType type) {
+        // We need to set again the movement method after a text change because Android resets the
+        // movement method to the default one in the case where the text cannot be selected and
+        // text links are clickable (which is the default case in NewPipe).
+        final MovementMethod movementMethod = this.getMovementMethod();
+        super.setText(text, type);
+        setMovementMethod(movementMethod);
+    }
+
     @Override
     public boolean onTextContextMenuItem(final int id) {
         if (id == android.R.id.shareText) {