Bitmap eraser tool (#507)

src/components/bit-eraser-mode/bit-eraser-mode.jsx

@@ -1,27 +1,26 @@
 import React from 'react';
+import PropTypes from 'prop-types';
 
-import {ComingSoonTooltip} from '../coming-soon/coming-soon.jsx';
 import ToolSelectComponent from '../tool-select-base/tool-select-base.jsx';
 
 import eraserIcon from './eraser.svg';
 
-const BitEraserComponent = () => (
-    <ComingSoonTooltip
-        place="right"
-        tooltipId="bit-eraser-mode"
-    >
+const BitEraserComponent = props => (
     <ToolSelectComponent
-            disabled
         imgDescriptor={{
             defaultMessage: 'Eraser',
             description: 'Label for the eraser tool',
             id: 'paint.eraserMode.eraser'
         }}
         imgSrc={eraserIcon}
-            isSelected={false}
-            onMouseDown={function () {}} // eslint-disable-line react/jsx-no-bind
+        isSelected={props.isSelected}
+        onMouseDown={props.onMouseDown}
     />
-    </ComingSoonTooltip>
 );
 
+BitEraserComponent.propTypes = {
+    isSelected: PropTypes.bool.isRequired,
+    onMouseDown: PropTypes.func.isRequired
+};
+
 export default BitEraserComponent;

src/components/mode-tools/mode-tools.jsx

@@ -7,6 +7,7 @@ import React from 'react';
 import {changeBrushSize} from '../../reducers/brush-mode';
 import {changeBrushSize as changeEraserSize} from '../../reducers/eraser-mode';
 import {changeBitBrushSize} from '../../reducers/bit-brush-size';
+import {changeBitEraserSize} from '../../reducers/bit-eraser-size';
 
 import FontDropdown from '../../containers/font-dropdown.jsx';
 import LiveInputHOC from '../forms/live-input-hoc.jsx';
@@ -23,6 +24,7 @@ import copyIcon from './icons/copy.svg';
 import pasteIcon from './icons/paste.svg';
 
 import bitBrushIcon from '../bit-brush-mode/brush.svg';
+import bitEraserIcon from '../bit-eraser-mode/eraser.svg';
 import bitLineIcon from '../bit-line-mode/line.svg';
 import brushIcon from '../brush-mode/brush.svg';
 import curvedPointIcon from './icons/curved-point.svg';
@@ -117,7 +119,13 @@ const ModeToolsComponent = props => {
             </div>
         );
     }
+    case Modes.BIT_ERASER:
+        /* falls through */
     case Modes.ERASER:
+    {
+        const currentIcon = isVector(props.format) ? eraserIcon : bitEraserIcon;
+        const currentEraserValue = isBitmap(props.format) ? props.bitEraserSize : props.eraserValue;
+        const changeFunction = isBitmap(props.format) ? props.onBitEraserSliderChange : props.onEraserSliderChange;
         return (
             <div className={classNames(props.className, styles.modeTools)}>
                 <div>
@@ -125,7 +133,7 @@ const ModeToolsComponent = props => {
                         alt={props.intl.formatMessage(messages.eraserSize)}
                         className={styles.modeToolsIcon}
                         draggable={false}
-                        src={eraserIcon}
+                        src={currentIcon}
                     />
                 </div>
                 <LiveInput
@@ -134,11 +142,12 @@ const ModeToolsComponent = props => {
                     max={MAX_STROKE_WIDTH}
                     min="1"
                     type="number"
-                    value={props.eraserValue}
-                    onSubmit={props.onEraserSliderChange}
+                    value={currentEraserValue}
+                    onSubmit={changeFunction}
                 />
             </div>
         );
+    }
     case Modes.RESHAPE:
         return (
             <div className={classNames(props.className, styles.modeTools)}>
@@ -207,6 +216,7 @@ const ModeToolsComponent = props => {
 
 ModeToolsComponent.propTypes = {
     bitBrushSize: PropTypes.number,
+    bitEraserSize: PropTypes.number,
     brushValue: PropTypes.number,
     className: PropTypes.string,
     clipboardItems: PropTypes.arrayOf(PropTypes.array),
@@ -233,6 +243,7 @@ const mapStateToProps = state => ({
     mode: state.scratchPaint.mode,
     format: state.scratchPaint.format,
     bitBrushSize: state.scratchPaint.bitBrushSize,
+    bitEraserSize: state.scratchPaint.bitEraserSize,
     brushValue: state.scratchPaint.brushMode.brushSize,
     clipboardItems: state.scratchPaint.clipboard.items,
     eraserValue: state.scratchPaint.eraserMode.brushSize,
@@ -245,6 +256,9 @@ const mapDispatchToProps = dispatch => ({
     onBitBrushSliderChange: bitBrushSize => {
         dispatch(changeBitBrushSize(bitBrushSize));
     },
+    onBitEraserSliderChange: eraserSize => {
+        dispatch(changeBitEraserSize(eraserSize));
+    },
     onEraserSliderChange: eraserSize => {
         dispatch(changeEraserSize(eraserSize));
     }

src/components/paint-editor/paint-editor.jsx

@@ -12,7 +12,7 @@ import BitOvalMode from '../../components/bit-oval-mode/bit-oval-mode.jsx';
 import BitRectMode from '../../containers/bit-rect-mode.jsx';
 import BitTextMode from '../../components/bit-text-mode/bit-text-mode.jsx';
 import BitFillMode from '../../components/bit-fill-mode/bit-fill-mode.jsx';
-import BitEraserMode from '../../components/bit-eraser-mode/bit-eraser-mode.jsx';
+import BitEraserMode from '../../containers/bit-eraser-mode.jsx';
 import BitSelectMode from '../../components/bit-select-mode/bit-select-mode.jsx';
 import Box from '../box/box.jsx';
 import Button from '../button/button.jsx';
@@ -182,7 +182,9 @@ const PaintEditorComponent = props => (
                     />
                     <BitTextMode />
                     <BitFillMode />
-                    <BitEraserMode />
+                    <BitEraserMode
+                        onUpdateImage={props.onUpdateImage}
+                    />
                     <BitSelectMode />
                 </div>
             ) : null}

src/containers/bit-eraser-mode.jsx

@@ -0,0 +1,90 @@
+import PropTypes from 'prop-types';
+import React from 'react';
+import {connect} from 'react-redux';
+import bindAll from 'lodash.bindall';
+import Modes from '../lib/modes';
+
+import {changeMode} from '../reducers/modes';
+import {clearSelectedItems} from '../reducers/selected-items';
+import {clearSelection} from '../helper/selection';
+
+import BitEraserModeComponent from '../components/bit-eraser-mode/bit-eraser-mode.jsx';
+import BitBrushTool from '../helper/bit-tools/brush-tool';
+
+class BitEraserMode extends React.Component {
+    constructor (props) {
+        super(props);
+        bindAll(this, [
+            'activateTool',
+            'deactivateTool'
+        ]);
+    }
+    componentDidMount () {
+        if (this.props.isBitEraserModeActive) {
+            this.activateTool(this.props);
+        }
+    }
+    componentWillReceiveProps (nextProps) {
+        if (this.tool && nextProps.bitEraserSize !== this.props.bitEraserSize) {
+            this.tool.setBrushSize(nextProps.bitEraserSize);
+        }
+        
+        if (nextProps.isBitEraserModeActive && !this.props.isBitEraserModeActive) {
+            this.activateTool();
+        } else if (!nextProps.isBitEraserModeActive && this.props.isBitEraserModeActive) {
+            this.deactivateTool();
+        }
+    }
+    shouldComponentUpdate (nextProps) {
+        return nextProps.isBitEraserModeActive !== this.props.isBitEraserModeActive;
+    }
+    activateTool () {
+        clearSelection(this.props.clearSelectedItems);
+        this.tool = new BitBrushTool(
+            this.props.onUpdateImage,
+            true /* isEraser */
+        );
+        this.tool.setBrushSize(this.props.bitEraserSize);
+
+        this.tool.activate();
+    }
+    deactivateTool () {
+        this.tool.deactivateTool();
+        this.tool.remove();
+        this.tool = null;
+    }
+    render () {
+        return (
+            <BitEraserModeComponent
+                isSelected={this.props.isBitEraserModeActive}
+                onMouseDown={this.props.handleMouseDown}
+            />
+        );
+    }
+}
+
+BitEraserMode.propTypes = {
+    bitEraserSize: PropTypes.number.isRequired,
+    clearSelectedItems: PropTypes.func.isRequired,
+    handleMouseDown: PropTypes.func.isRequired,
+    isBitEraserModeActive: PropTypes.bool.isRequired,
+    onUpdateImage: PropTypes.func.isRequired
+};
+
+const mapStateToProps = state => ({
+    bitEraserSize: state.scratchPaint.bitEraserSize,
+    isBitEraserModeActive: state.scratchPaint.mode === Modes.BIT_ERASER
+});
+const mapDispatchToProps = dispatch => ({
+    clearSelectedItems: () => {
+        dispatch(clearSelectedItems());
+    },
+    handleMouseDown: () => {
+        dispatch(changeMode(Modes.BIT_ERASER));
+    }
+});
+
+export default connect(
+    mapStateToProps,
+    mapDispatchToProps
+)(BitEraserMode);

src/containers/paint-editor.jsx

@@ -124,6 +124,9 @@ class PaintEditor extends React.Component {
             case Modes.BIT_RECT:
                 this.props.changeMode(Modes.RECT);
                 break;
+            case Modes.BIT_ERASER:
+                this.props.changeMode(Modes.ERASER);
+                break;
             default:
                 this.props.changeMode(Modes.BRUSH);
             }
@@ -138,6 +141,9 @@ class PaintEditor extends React.Component {
             case Modes.RECT:
                 this.props.changeMode(Modes.BIT_RECT);
                 break;
+            case Modes.ERASER:
+                this.props.changeMode(Modes.BIT_ERASER);
+                break;
             default:
                 this.props.changeMode(Modes.BIT_BRUSH);
             }

src/helper/bit-tools/brush-tool.js

@@ -4,15 +4,17 @@ import {forEachLinePoint, getBrushMark} from '../bitmap';
 import {getGuideLayer} from '../layer';
 
 /**
- * Tool for drawing with the bitmap brush.
+ * Tool for drawing with the bitmap brush and eraser
  */
 class BrushTool extends paper.Tool {
     /**
      * @param {!function} onUpdateImage A callback to call when the image visibly changes
+     * @param {boolean} isEraser True if brush should erase
      */
-    constructor (onUpdateImage) {
+    constructor (onUpdateImage, isEraser) {
         super();
         this.onUpdateImage = onUpdateImage;
+        this.isEraser = isEraser;
         
         // We have to set these functions instead of just declaring them because
         // paper.js tools hook up the listeners in the setter functions.
@@ -39,7 +41,14 @@ class BrushTool extends paper.Tool {
             this.tmpCanvas = getBrushMark(this.size, this.color);
         }
         const roundedUpRadius = Math.ceil(this.size / 2);
+        const context = getRaster().getContext('2d');
+        if (this.isEraser) {
+            context.globalCompositeOperation = 'destination-out';
+        }
         getRaster().drawImage(this.tmpCanvas, new paper.Point(~~x - roundedUpRadius, ~~y - roundedUpRadius));
+        if (this.isEraser) {
+            context.globalCompositeOperation = 'source-over';
+        }
     }
     updateCursorIfNeeded () {
         if (!this.size) {
@@ -57,7 +66,7 @@ class BrushTool extends paper.Tool {
                 this.cursorPreview.remove();
             }
 
-            this.tmpCanvas = getBrushMark(this.size, this.color);
+            this.tmpCanvas = getBrushMark(this.size, this.color, this.isEraser);
             this.cursorPreview = new paper.Raster(this.tmpCanvas);
             this.cursorPreview.guide = true;
             this.cursorPreview.parent = getGuideLayer();

src/helper/bitmap.js

@@ -86,9 +86,10 @@ const fillEllipse = function (centerX, centerY, radiusX, radiusY, context) {
 /**
  * @param {!number} size The diameter of the brush
  * @param {!string} color The css color of the brush
+ * @param {?boolean} isEraser True if we want the brush mark for the eraser
  * @return {HTMLCanvasElement} a canvas with the brush mark printed on it
  */
-const getBrushMark = function (size, color) {
+const getBrushMark = function (size, color, isEraser) {
     size = ~~size;
     const canvas = document.createElement('canvas');
     const roundedUpRadius = Math.ceil(size / 2);
@@ -96,7 +97,8 @@ const getBrushMark = function (size, color) {
     canvas.height = roundedUpRadius * 2;
     const context = canvas.getContext('2d');
     context.imageSmoothingEnabled = false;
-    context.fillStyle = color;
+    context.fillStyle = isEraser ? 'white' : color;
+    // @todo add outline for erasers
     // Small squares for pixel artists
     if (size <= 5) {
         if (size % 2) {

src/lib/modes.js

@@ -4,6 +4,7 @@ const Modes = keyMirror({
     BIT_BRUSH: null,
     BIT_LINE: null,
     BIT_RECT: null,
+    BIT_ERASER: null,
     BRUSH: null,
     ERASER: null,
     LINE: null,
@@ -19,7 +20,8 @@ const Modes = keyMirror({
 const BitmapModes = keyMirror({
     BIT_BRUSH: null,
     BIT_LINE: null,
-    BIT_RECT: null
+    BIT_RECT: null,
+    BIT_ERASER: null
 });
 
 export {

src/reducers/bit-eraser-size.js

@@ -0,0 +1,31 @@
+import log from '../log/log';
+
+const CHANGE_BIT_ERASER_SIZE = 'scratch-paint/eraser-mode/CHANGE_BIT_ERASER_SIZE';
+const initialState = 40;
+
+const reducer = function (state, action) {
+    if (typeof state === 'undefined') state = initialState;
+    switch (action.type) {
+    case CHANGE_BIT_ERASER_SIZE:
+        if (isNaN(action.eraserSize)) {
+            log.warn(`Invalid eraser size: ${action.eraserSize}`);
+            return state;
+        }
+        return Math.max(1, action.eraserSize);
+    default:
+        return state;
+    }
+};
+
+// Action creators ==================================
+const changeBitEraserSize = function (eraserSize) {
+    return {
+        type: CHANGE_BIT_ERASER_SIZE,
+        eraserSize: eraserSize
+    };
+};
+
+export {
+    reducer as default,
+    changeBitEraserSize
+};

src/reducers/scratch-paint-reducer.js

@@ -1,6 +1,7 @@
 import {combineReducers} from 'redux';
 import modeReducer from './modes';
 import bitBrushSizeReducer from './bit-brush-size';
+import bitEraserSizeReducer from './bit-eraser-size';
 import brushModeReducer from './brush-mode';
 import eraserModeReducer from './eraser-mode';
 import colorReducer from './color';
@@ -17,6 +18,7 @@ import undoReducer from './undo';
 export default combineReducers({
     mode: modeReducer,
     bitBrushSize: bitBrushSizeReducer,
+    bitEraserSize: bitEraserSizeReducer,
     brushMode: brushModeReducer,
     color: colorReducer,
     clipboard: clipboardReducer,