restaurant-search/prototype/grapher.js

"use strict";

goog.require('goog.color');
goog.require('goog.math');
goog.require('goog.math.Coordinate');
goog.require('goog.math.Range');
goog.require('goog.math.Rect');

function Column(canvas, name, params, range, saturation, bounds) {
    this.clearShapes = function() {
        for (var i = 0, count = this.shapes.length; i < count; ++i) {
            this.canvas.remove(this.shapes[i]);
        }

        this.shapes = [];
    }

    this.updateShapes = function(final) {
        this.labelBounds  = this.getLabelBounds(this.bounds);
        this.columnBounds = this.getColumnBounds(this.bounds);
        this.hintBounds   = this.getHintBounds(this.columnBounds);
        this.fillBounds   = this.getFillBounds(this.columnBounds);
        this.handleBounds = this.getHandleBounds(this.columnBounds, this.fillBounds);

        if (final) {
            this.updateRect('boundsRect', {
                left:   this.bounds.left,
                top:    this.bounds.top,
                width:  this.bounds.width,
                height: this.bounds.height,
                stroke: this.strokeColor,
                fill:   this.emptyColor
            });

            this.updateRect('hintRect', {
                left:   this.hintBounds.left,
                top:    this.hintBounds.top,
                width:  this.hintBounds.width,
                height: this.hintBounds.height,
                stroke: this.strokeColor
            });

            this.hintRect.setGradient('fill', {
                x1:         0.0,
                y1:         -this.hintRect.height / 2,
                x2:         0.0,
                y2:         this.hintRect.height / 2,
                colorStops: this.decimateHints(this.hintSteps, this.hintSaturation)
            });

            this.updateRect('labelRect', {
                left:   this.labelBounds.left,
                top:    this.labelBounds.top,
                width:  this.labelBounds.width,
                height: this.labelBounds.height,
                fill:   this.strokeColor
            });

            this.updateText('label', this.name, {
                left:     this.fillBounds.left + this.fillBounds.width / 2,
                top:      this.labelBounds.top + this.labelBounds.height / 2,
                fontSize: this.labelFontSize,
                originX:  'center',
                originY:  'center',
            });
        }

        this.updateRect('fillRect', {
            left:   this.fillBounds.left,
            top:    this.fillBounds.top,
            width:  this.fillBounds.width,
            height: this.fillBounds.height,
            fill:   this.fillColor
        });

        this.updateRect('handleRect', {
            left:   this.handleBounds.left,
            top:    this.handleBounds.top,
            width:  this.handleBounds.width,
            height: this.handleBounds.height,
            fill:   this.handleColor
        });

        this.canvas.renderAll();
    }

    this.updateRect = function(name, args) {
        if (name in this) {
            this[name].set(args);
        }
        else {
            var rect = new fabric.Rect(args);
            this.canvas.add(rect);
            this.shapes.push(rect);
            this[name] = rect;
        }
    }

    this.updateText = function(name, text, args) {
        if (name in this) {
            this[name].set(args);
        }
        else {
            var text = new fabric.Text(text, args);
            this.canvas.add(text);
            this.shapes.push(text);
            this[name] = text;
        }
    }

    this.updateColor = function(color) {
        var fillColorRgb   = goog.color.hexToRgb(goog.color.parse(color).hex);
        var handleColorRgb = goog.color.darken(fillColorRgb, this.handleDarken);

        this.fillColor   = goog.color.rgbToHex.apply(this, fillColorRgb);
        this.handleColor = goog.color.rgbToHex.apply(this, handleColorRgb);
    }

    this.decimateHints = function(steps, saturation) {
        var groups = this.groupHints(steps);

        var colorStops = {};
        groups.forEach(function(count, index) {
            var colorByte = 0xff - Math.min(0xff, Math.round(0xff * count / saturation));
            var colorStr  = goog.color.rgbToHex(colorByte, colorByte, colorByte);
            colorStops[String(index / steps)] = colorStr;
        });

        return colorStops;
    }

    this.groupHints = function(steps) {
        var stepSize = this.range.getLength() / steps;

        var hintGroups = [];
        for (var i = 0; i < steps; ++i) {
            var stepMax = this.range.end - stepSize * i;
            var stepMin = stepMax - stepSize;

            var hintCount = 0;
            this.hints.forEach(function(hint) {
                if (hint > stepMin && hint <= stepMax) {
                    ++hintCount;
                }
            });

            hintGroups.push(hintCount);
        }

        return hintGroups;
    }

    this.setClampedValue = function(value, final) {
        this.value = goog.math.clamp(value, this.range.start, this.range.end);
        this.updateShapes(final);

        if (this.onValueChanged && final) {
            this.onValueChanged.call(this.onValueChangedObj, this.name, this.value);
        }
    }

    this.setHints = function(hints) {
        this.hints = hints;
        this.updateShapes(true);
    }

    this.getLabelBounds = function(bounds) {
        return new goog.math.Rect(
            bounds.left,
            bounds.top + bounds.height - this.labelSize,
            bounds.width,
            this.labelSize
        );
    }

    this.getColumnBounds = function(bounds) {
        return new goog.math.Rect(
            bounds.left,
            bounds.top,
            bounds.width,
            bounds.height - this.labelSize
        );
    }

    this.getHintBounds = function(bounds) {
        return new goog.math.Rect(
            bounds.left + bounds.width - this.hintSize,
            bounds.top,
            this.hintSize,
            bounds.height
        );
    }

    this.getFillBounds = function(bounds) {
        var fill = (this.value - this.range.start) / this.range.getLength();
        var height = bounds.height * (1.0 - goog.math.clamp(fill, 0.0, 1.0));
        return new goog.math.Rect(
            bounds.left,
            bounds.top + height,
            bounds.width - this.hintSize,
            bounds.height - height
        );
    }

    this.getHandleBounds = function(bounds, fillBounds) {
        var handleBounds = new goog.math.Rect(
            fillBounds.left,
            fillBounds.top,
            fillBounds.width,
            this.handleSize
        );
        handleBounds.intersection(bounds);
        return handleBounds;
    }

    this.mouseDown = function(position) {
        if (this.isGrabbing(position)) {
            this.stateTransition(this.State.DRAG, position);
        }
    }

    this.mouseUp = function(position) {
        this.stateTransition(
            this.isHovering(position) ? this.State.HOVER : this.State.NORMAL,
            position
        );
    }

    this.mouseMove = function(position) {
        switch (this.state) {
            case this.State.NORMAL:
                if (this.isHovering(position)) {
                    this.stateTransition(this.State.HOVER, position);
                }
                break;
            case this.State.HOVER:
                if (!this.isHovering(position)) {
                    this.stateTransition(this.State.NORMAL, position);
                }
                break;
        }

        this.stateUpdate(position);
    }

    this.mouseOut = function(position) {
        this.mouseUp(position);
    }

    this.mouseDoubleClick = function(position) {
        if (this.isContained(position)) {
            this.setClampedValue(this.getValueFromPos(position), true);
        }
    }

    this.getValueFromPos = function(position) {
        var percent = 1.0 - (position.y - this.columnBounds.top) / this.columnBounds.height;
        return this.range.start + this.range.getLength() * percent;
    }

    this.isHovering = function(position) {
        return this.isGrabbing(position);
    }

    this.isGrabbing = function(position) {
        return this.handleBounds.contains(position);
    }

    this.isContained = function(position) {
        return this.columnBounds.contains(position);
    }

    this.stateUpdate = function(position) {
        switch (this.state) {
            case this.State.DRAG:
                this.setClampedValue(this.getValueFromPos(position) + this.dragDelta, false);
                break;
        }
    }

    this.stateTransition = function(state, position) {
        if (state == this.state) {
            return;
        }

        switch (this.state) {
            case this.State.DRAG:
                this.setClampedValue(this.getValueFromPos(position) + this.dragDelta, true);
            case this.State.HOVER:
                if (state == this.State.NORMAL) {
                    this.canvas.contextContainer.canvas.style.cursor = 'default';
                }
                break;
        }

        switch (state) {
            case this.State.DRAG:
                this.dragDelta = this.value - this.getValueFromPos(position);
            case this.State.HOVER:
                this.canvas.contextContainer.canvas.style.cursor = 'ns-resize';
                break;
        }

        this.state = state;
    }

    this.State = {
        NORMAL: 0,
        HOVER:  1,
        DRAG:   2
    };

    this.handleSize     = 10;
    this.handleDarken   = 0.25;
    this.hintSaturation = saturation;
    this.hintSize       = 5;
    this.hintSteps      = 10;
    this.labelFontSize  = 15;
    this.labelSize      = 20;
    this.emptyColor     = '#eeeeec';
    this.strokeColor    = '#d3d7cf';

    this.canvas = canvas;
    this.shapes = [];
    this.name   = name;
    this.value  = params.value;
    this.hints  = params.hints;
    this.range  = range;
    this.bounds = bounds;
    this.state  = this.State.NORMAL;

    this.updateColor(params.color);
    this.updateShapes(true);
}

function Grapher(canvas) {
    this.setColumns = function(columns) {
        this.columns.forEach(function(c) { c.clearShapes(); });
        this.columns  = [];
        this.indexMap = {};

        var graphBounds = this.getGraphBounds(this.getCanvasBounds());
        var columnCount = Object.keys(columns).length;

        var saturation = 0;
        for (var columnName in columns) {
            saturation = Math.max(columns[columnName].hints.length, saturation);
        }

        var index = 0;
        for (var columnName in columns) {
            this.indexMap[columnName] = index;
            this.columns.push(new Column(
                this.canvas,
                columnName,
                columns[columnName],
                this.range,
                saturation,
                this.getColumnBounds(graphBounds, index++, columnCount)
            ));
        }
    }

    this.setColumnHints = function(name, hints) {
        var index = this.getColumnIndex(name);
        if (index < this.columns.length) {
            this.columns[index].setHints(hints);
        }
    }

    this.setValueChangedListener = function(listener, object) {
        this.columns.forEach(function (c) {
            c.onValueChanged    = listener;
            c.onValueChangedObj = object;
        });
    }

    this.getColumnCount = function() {
        return this.columns.length;
    }

    this.getColumnIndex = function(name) {
        return this.indexMap[name];
    }

    this.getColumnName = function(index) {
        return this.columns[index].name;
    }

    this.getCanvasBounds = function() {
        return new goog.math.Rect(0, 0, this.canvas.width - 1, this.canvas.height - 1);
    }

    this.getGraphBounds = function(bounds) {
        return this.getCanvasBounds();
    }

    this.getColumnBounds = function(bounds, index, count) {
        var secWidth = bounds.width / count;
        var columnWidth = secWidth - this.padding * 2;
        return new goog.math.Rect(
            bounds.left + secWidth * index + this.padding,
            bounds.top,
            columnWidth,
            bounds.height
        );
    }

    this.getMousePos = function(e) {
        var rect = e.target.getBoundingClientRect();
        return new goog.math.Coordinate(
            e.clientX - rect.left,
            e.clientY - rect.top
        );
    }

    this.mouseDown = function(e) {
        var position = this.grapher.getMousePos(e);
        this.grapher.columns.forEach(function(g) {
            g.mouseDown(position);
        });
    }

    this.mouseUp = function(e) {
        var position = this.grapher.getMousePos(e);
        this.grapher.columns.forEach(function(g) {
            g.mouseUp(position);
        });
    }

    this.mouseMove = function(e) {
        var position = this.grapher.getMousePos(e);
        this.grapher.columns.forEach(function(g) {
            g.mouseMove(position);
        });
    }

    this.mouseOut = function(e) {
        var position = this.grapher.getMousePos(e);
        this.grapher.columns.forEach(function(g) {
            g.mouseOut(position);
        });
    }

    this.mouseDoubleClick = function(e) {
        var position = this.grapher.getMousePos(e);
        this.grapher.columns.forEach(function(g) {
            g.mouseDoubleClick(position);
        });
    }

    this.canvas   = new fabric.StaticCanvas(canvas);
    this.range    = new goog.math.Range(0.0, 1.0);
    this.padding  = 5;
    this.indexMap = {};
    this.columns  = [];

    var c = this.canvas.contextContainer.canvas;
    c.addEventListener('mousedown', this.mouseDown, false);
    c.addEventListener('mouseup', this.mouseUp, false);
    c.addEventListener('mousemove', this.mouseMove, false);
    c.addEventListener('mouseout', this.mouseOut, false);
    c.addEventListener('dblclick', this.mouseDoubleClick, false);
    c.grapher = this;
}