Add QR group link share.

app/src/main/java/org/thoughtcrime/securesms/components/qr/QrView.java

@@ -0,0 +1,93 @@
+package org.thoughtcrime.securesms.components.qr;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.util.AttributeSet;
+import android.util.Log;
+
+import androidx.annotation.ColorInt;
+import androidx.annotation.Nullable;
+import androidx.annotation.WorkerThread;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.WriterException;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.qrcode.QRCodeWriter;
+
+import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.components.SquareImageView;
+import org.thoughtcrime.securesms.qr.QrCode;
+import org.thoughtcrime.securesms.util.Stopwatch;
+import org.thoughtcrime.securesms.util.concurrent.SerialMonoLifoExecutor;
+import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
+import org.thoughtcrime.securesms.util.concurrent.SimpleTask;
+
+import java.util.concurrent.Executor;
+
+/**
+ * Generates a bitmap asynchronously for the supplied {@link BitMatrix} data and displays it.
+ */
+public class QrView extends SquareImageView {
+
+  private static final @ColorInt int DEFAULT_FOREGROUND_COLOR = Color.BLACK;
+  private static final @ColorInt int DEFAULT_BACKGROUND_COLOR = Color.TRANSPARENT;
+
+  private @Nullable Bitmap qrBitmap;
+  private @ColorInt int    foregroundColor;
+  private @ColorInt int    backgroundColor;
+
+  public QrView(Context context) {
+    super(context);
+    init(null);
+  }
+
+  public QrView(Context context, AttributeSet attrs) {
+    super(context, attrs);
+    init(attrs);
+  }
+
+  public QrView(Context context, AttributeSet attrs, int defStyleAttr) {
+    super(context, attrs, defStyleAttr);
+    init(attrs);
+  }
+
+  private void init(@Nullable AttributeSet attrs) {
+    if (attrs != null) {
+      TypedArray typedArray = getContext().getTheme().obtainStyledAttributes(attrs, R.styleable.QrView, 0, 0);
+      foregroundColor = typedArray.getColor(R.styleable.QrView_qr_foreground_color, DEFAULT_FOREGROUND_COLOR);
+      backgroundColor = typedArray.getColor(R.styleable.QrView_qr_background_color, DEFAULT_BACKGROUND_COLOR);
+      typedArray.recycle();
+    } else {
+      foregroundColor = DEFAULT_FOREGROUND_COLOR;
+      backgroundColor = DEFAULT_BACKGROUND_COLOR;
+    }
+
+    if (isInEditMode()) {
+      setQrText("https://signal.org");
+    }
+  }
+
+  public void setQrText(@Nullable String text) {
+    setQrBitmap(QrCode.create(text, foregroundColor, backgroundColor));
+  }
+
+  private void setQrBitmap(@Nullable Bitmap qrBitmap) {
+    if (this.qrBitmap == qrBitmap) {
+      return;
+    }
+
+    if (this.qrBitmap != null) {
+      this.qrBitmap.recycle();
+    }
+
+    this.qrBitmap = qrBitmap;
+
+    setImageBitmap(this.qrBitmap);
+  }
+
+  public @Nullable Bitmap getQrBitmap() {
+    return qrBitmap;
+  }
+}