1 files changed, 217 insertions, 0 deletions
diff --git a/ui/src/main/java/com/wireguard/android/widget/SlashDrawable.java b/ui/src/main/java/com/wireguard/android/widget/SlashDrawable.java
new file mode 100644
index 00000000..e020aa81
--- /dev/null
+++ b/ui/src/main/java/com/wireguard/android/widget/SlashDrawable.java
@@ -0,0 +1,217 @@
+/*
+ * Copyright © 2018 The Android Open Source Project
+ * Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.widget;
+
+import android.animation.ObjectAnimator;
+import android.animation.ValueAnimator;
+import android.content.res.ColorStateList;
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Matrix;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.graphics.Path.Direction;
+import android.graphics.PixelFormat;
+import android.graphics.PorterDuff.Mode;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.graphics.Region;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import androidx.annotation.ColorInt;
+import androidx.annotation.IntRange;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import android.util.FloatProperty;
+
+@RequiresApi(Build.VERSION_CODES.N)
+public class SlashDrawable extends Drawable {
+
+    private static final float CENTER_X = 10.65f;
+    private static final float CENTER_Y = 11.869239f;
+    private static final float CORNER_RADIUS = Build.VERSION.SDK_INT < Build.VERSION_CODES.O ? 0f : 1f;
+    // Draw the slash washington-monument style; rotate to no-u-turn style
+    private static final float DEFAULT_ROTATION = -45f;
+    private static final long QS_ANIM_LENGTH = 350;
+    private static final float SCALE = 24f;
+    private static final float SLASH_HEIGHT = 28f;
+    // These values are derived in un-rotated (vertical) orientation
+    private static final float SLASH_WIDTH = 1.8384776f;
+    // Bottom is derived during animation
+    private static final float LEFT = (CENTER_X - (SLASH_WIDTH / 2)) / SCALE;
+    private static final float RIGHT = (CENTER_X + (SLASH_WIDTH / 2)) / SCALE;
+    private static final float TOP = (CENTER_Y - (SLASH_HEIGHT / 2)) / SCALE;
+    private static final FloatProperty mSlashLengthProp = new FloatProperty<SlashDrawable>("slashLength") {
+        @Override
+        public Float get(final SlashDrawable object) {
+            return object.mCurrentSlashLength;
+        }
+
+        @Override
+        public void setValue(final SlashDrawable object, final float value) {
+            object.mCurrentSlashLength = value;
+        }
+    };
+    private final Drawable mDrawable;
+    private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+    private final Path mPath = new Path();
+    private final RectF mSlashRect = new RectF(0, 0, 0, 0);
+    private boolean mAnimationEnabled = true;
+    // Animate this value on change
+    private float mCurrentSlashLength;
+    private float mRotation;
+    private boolean mSlashed;
+
+    public SlashDrawable(final Drawable d) {
+        mDrawable = d;
+    }
+
+    @SuppressWarnings("deprecation")
+    @Override
+    public void draw(final Canvas canvas) {
+        canvas.save();
+        final Matrix m = new Matrix();
+        final int width = getBounds().width();
+        final int height = getBounds().height();
+        final float radiusX = scale(CORNER_RADIUS, width);
+        final float radiusY = scale(CORNER_RADIUS, height);
+        updateRect(
+                scale(LEFT, width),
+                scale(TOP, height),
+                scale(RIGHT, width),
+                scale(TOP + mCurrentSlashLength, height)
+        );
+
+        mPath.reset();
+        // Draw the slash vertically
+        mPath.addRoundRect(mSlashRect, radiusX, radiusY, Direction.CW);
+        // Rotate -45 + desired rotation
+        m.setRotate(mRotation + DEFAULT_ROTATION, width / 2, height / 2);
+        mPath.transform(m);
+        canvas.drawPath(mPath, mPaint);
+
+        // Rotate back to vertical
+        m.setRotate(-mRotation - DEFAULT_ROTATION, width / 2, height / 2);
+        mPath.transform(m);
+
+        // Draw another rect right next to the first, for clipping
+        m.setTranslate(mSlashRect.width(), 0);
+        mPath.transform(m);
+        mPath.addRoundRect(mSlashRect, 1.0f * width, 1.0f * height, Direction.CW);
+        m.setRotate(mRotation + DEFAULT_ROTATION, width / 2, height / 2);
+        mPath.transform(m);
+
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
+            canvas.clipPath(mPath, Region.Op.DIFFERENCE);
+        else
+            canvas.clipOutPath(mPath);
+
+        mDrawable.draw(canvas);
+        canvas.restore();
+    }
+
+    @Override
+    public int getIntrinsicHeight() {
+        return mDrawable.getIntrinsicHeight();
+    }
+
+    @Override
+    public int getIntrinsicWidth() {
+        return mDrawable.getIntrinsicWidth();
+    }
+
+    @SuppressWarnings("deprecation")
+    @Override
+    public int getOpacity() {
+        return PixelFormat.OPAQUE;
+    }
+
+    @Override
+    protected void onBoundsChange(final Rect bounds) {
+        super.onBoundsChange(bounds);
+        mDrawable.setBounds(bounds);
+    }
+
+    private float scale(final float frac, final int width) {
+        return frac * width;
+    }
+
+    @Override
+    public void setAlpha(@IntRange(from = 0, to = 255) final int alpha) {
+        mDrawable.setAlpha(alpha);
+        mPaint.setAlpha(alpha);
+    }
+
+    public void setAnimationEnabled(final boolean enabled) {
+        mAnimationEnabled = enabled;
+    }
+
+    @Override
+    public void setColorFilter(@Nullable final ColorFilter colorFilter) {
+        mDrawable.setColorFilter(colorFilter);
+        mPaint.setColorFilter(colorFilter);
+    }
+
+    private void setDrawableTintList(@Nullable final ColorStateList tint) {
+        mDrawable.setTintList(tint);
+    }
+
+    public void setRotation(final float rotation) {
+        if (mRotation == rotation)
+            return;
+        mRotation = rotation;
+        invalidateSelf();
+    }
+
+    @SuppressWarnings("unchecked")
+    public void setSlashed(final boolean slashed) {
+        if (mSlashed == slashed) return;
+
+        mSlashed = slashed;
+
+        final float end = mSlashed ? SLASH_HEIGHT / SCALE : 0f;
+        final float start = mSlashed ? 0f : SLASH_HEIGHT / SCALE;
+
+        if (mAnimationEnabled) {
+            final ObjectAnimator anim = ObjectAnimator.ofFloat(this, mSlashLengthProp, start, end);
+            anim.addUpdateListener((ValueAnimator valueAnimator) -> invalidateSelf());
+            anim.setDuration(QS_ANIM_LENGTH);
+            anim.start();
+        } else {
+            mCurrentSlashLength = end;
+            invalidateSelf();
+        }
+    }
+
+    @Override
+    public void setTint(@ColorInt final int tintColor) {
+        super.setTint(tintColor);
+        mDrawable.setTint(tintColor);
+        mPaint.setColor(tintColor);
+    }
+
+    @Override
+    public void setTintList(@Nullable final ColorStateList tint) {
+        super.setTintList(tint);
+        setDrawableTintList(tint);
+        mPaint.setColor(tint == null ? 0 : tint.getDefaultColor());
+        invalidateSelf();
+    }
+
+    @Override
+    public void setTintMode(final Mode tintMode) {
+        super.setTintMode(tintMode);
+        mDrawable.setTintMode(tintMode);
+    }
+
+    private void updateRect(final float left, final float top, final float right, final float bottom) {
+        mSlashRect.left = left;
+        mSlashRect.top = top;
+        mSlashRect.right = right;
+        mSlashRect.bottom = bottom;
+    }
+}