Add source

app/src/main/java/com/hippo/widget/FloatingActionButton.java

@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2014-2015 Hippo Seven
+ *
+ * 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
+ * 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.hippo.widget;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.util.AttributeSet;
+import android.view.View;
+
+import com.hippo.util.UiUtils;
+import com.hippo.util.ViewUtils;
+
+public class FloatingActionButton extends View {
+
+    private static final int[] BACKGROUND_ATTR = {android.R.attr.colorBackground};
+    private static final int[] DRAWABLE_ATTR = {android.R.attr.drawable};
+
+    private static final int DRAWABLE_WIDTH = UiUtils.dp2pix(24);
+
+    private GasketDrawer mGasketDrawer;
+    private Drawable mDrawable;
+
+    public FloatingActionButton(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(context, attrs, 0, 0);
+    }
+
+    public FloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(context, attrs, defStyleAttr, 0);
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public FloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private void init(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        TypedArray a;
+
+        // Background color
+        a = context.obtainStyledAttributes(attrs, BACKGROUND_ATTR, defStyleAttr, defStyleRes);
+        int bgColor = a.getColor(0, Color.BLACK);
+        a.recycle();
+
+        // Drawable
+        a = context.obtainStyledAttributes(attrs, DRAWABLE_ATTR, defStyleAttr, defStyleRes);
+        mDrawable = a.getDrawable(0);
+        a.recycle();
+
+        mGasketDrawer = new GasketDrawer(this, bgColor);
+    }
+
+    protected void drawableStateChanged() {
+        int[] stateSet = getDrawableState();
+        mGasketDrawer.onStateChange(stateSet);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        setMeasuredDimension(ViewUtils.getSuitableSize(getSuggestedMinimumWidth(), widthMeasureSpec),
+                ViewUtils.getSuitableSize(getSuggestedMinimumHeight(), heightMeasureSpec));
+    }
+
+    protected void onDraw(Canvas canvas) {
+        mGasketDrawer.draw(canvas);
+
+        if (mDrawable != null) {
+            int left;
+            int top;
+            int right;
+            int bottom;
+            int width = getWidth();
+            int height = getHeight();
+            int halfDrawableWidth = DRAWABLE_WIDTH / 2;
+            left = width / 2 - halfDrawableWidth;
+            top = height / 2 - halfDrawableWidth;
+            right = left + DRAWABLE_WIDTH;
+            bottom = top + DRAWABLE_WIDTH;
+            mDrawable.setBounds(left, top, right, bottom);
+            mDrawable.draw(canvas);
+        }
+    }
+
+    public void setColor(int color) {
+        mGasketDrawer.setColor(color);
+    }
+
+    public void setDrawable(Drawable drawable) {
+        mDrawable = drawable;
+        invalidate();
+    }
+
+    static class GasketDrawer {
+
+        private static final int SHADOW_RADIOUS = UiUtils.dp2pix(3);
+        private static final int SHADOW_OFFSET_Y = UiUtils.dp2pix(1);
+        private static final int GASKET_PADDING = SHADOW_RADIOUS + SHADOW_OFFSET_Y; // 4dp
+        private static final int SHADOW_COLOR = 0x8a000000;
+
+        private View mView;
+
+        private int mColor;
+        private int mDarkerColor;
+        private Paint mPaint;
+
+        private RectF mBounds;
+
+        private boolean mIsDark;
+
+        private GasketDrawer(View view, int color) {
+            mView = view;
+            mBounds = new RectF();
+            mColor = color;
+            mDarkerColor = UiUtils.getDarkerColor(color);
+            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG);
+            mPaint.setColor(mColor);
+            mPaint.setStyle(Paint.Style.FILL);
+
+            mPaint.setShadowLayer(SHADOW_RADIOUS, 0, SHADOW_OFFSET_Y, SHADOW_COLOR);
+            ViewUtils.removeHardwareAccelerationSupport(mView);
+        }
+
+        protected void onStateChange(int[] stateSet) {
+            boolean enabled = false;
+            boolean pressed = false;
+            boolean focused = false;
+
+            for (int state : stateSet) {
+                if (state == android.R.attr.state_enabled) {
+                    enabled = true;
+                }
+                if (state == android.R.attr.state_focused) {
+                    focused = true;
+                }
+                if (state == android.R.attr.state_pressed) {
+                    pressed = true;
+                }
+            }
+
+            setDark(!enabled || pressed || focused);
+        }
+
+        private void setDark(boolean isDark) {
+            if (mIsDark != isDark) {
+                mIsDark = isDark;
+                updateColor();
+            }
+        }
+
+        private void updateColor() {
+            mPaint.setColor(mIsDark ? mDarkerColor : mColor);
+            invalidateSelf();
+        }
+
+        private void invalidateSelf() {
+            mView.invalidate();
+        }
+
+        public void draw(Canvas canvas) {
+            mBounds.left = GASKET_PADDING;
+            mBounds.top = GASKET_PADDING;
+            mBounds.right = mView.getWidth() - GASKET_PADDING;
+            mBounds.bottom = mView.getHeight() - GASKET_PADDING;
+            canvas.drawOval(mBounds, mPaint);
+        }
+
+        public void setColor(int color) {
+            mColor = color;
+            mDarkerColor = UiUtils.getDarkerColor(color);
+            updateColor();
+        }
+    }
+}