    /**
     * @class Ext.chart.axis.Axis
     * @extends Ext.chart.axis.Abstract
     *
     * Defines axis for charts. The axis position, type, style can be configured.
     * The axes are defined in an axes array of configuration objects where the type,
     * field, grid and other configuration options can be set. To know more about how
     * to create a Chart please check the Chart class documentation. Here's an example for the axes part:
     * An example of axis for a series (in this case for an area chart that has multiple layers of yFields) could be:
     *
     *     axes: [{
     *         type: 'Numeric',
     *         grid: true,
     *         position: 'left',
     *         fields: ['data1', 'data2', 'data3'],
     *         title: 'Number of Hits',
     *         grid: {
     *             odd: {
     *                 opacity: 1,
     *                 fill: '#ddd',
     *                 stroke: '#bbb',
     *                 'stroke-width': 1
     *             }
     *         },
     *         minimum: 0
     *     }, {
     *         type: 'Category',
     *         position: 'bottom',
     *         fields: ['name'],
     *         title: 'Month of the Year',
     *         grid: true,
     *         label: {
     *             rotate: {
     *                 degrees: 315
     *             }
     *         }
     *     }]
     *
     * In this case we use a `Numeric` axis for displaying the values of the Area series and a `Category` axis for displaying the names of
     * the store elements. The numeric axis is placed on the left of the screen, while the category axis is placed at the bottom of the chart.
     * Both the category and numeric axes have `grid` set, which means that horizontal and vertical lines will cover the chart background. In the
     * category axis the labels will be rotated so they can fit the space better.
     */
    Ext.define('Ext.chart.axis.Axis', {

        /* Begin Definitions */

        extend: 'Ext.chart.axis.Abstract',

        alternateClassName: 'Ext.chart.Axis',

        requires: ['Ext.draw.Draw'],

        /* End Definitions */

        /**
         * @cfg {Number} majorTickSteps
         * If `minimum` and `maximum` are specified it forces the number of major ticks to the specified value.
         */

        /**
         * @cfg {Number} minorTickSteps
         * The number of small ticks between two major ticks. Default is zero.
         */

        /**
         * @cfg {Number} dashSize
         * The size of the dash marker. Default's 3.
         */
        dashSize: 3,

        /**
         * @cfg {String} position
         * Where to set the axis. Available options are `left`, `bottom`, `right`, `top`. Default's `bottom`.
         */
        position: 'bottom',

        // @private
        skipFirst: false,

        /**
         * @cfg {Number} length
         * Offset axis position. Default's 0.
         */
        length: 0,

        /**
         * @cfg {Number} width
         * Offset axis width. Default's 0.
         */
        width: 0,

        majorTickSteps: false,

        // @private
        applyData: Ext.emptyFn,

        // @private creates a structure with start, end and step points.
        calcEnds: function() {
            var me = this,
                math = Math,
                mmax = math.max,
                mmin = math.min,
                store = me.chart.substore || me.chart.store,
                series = me.chart.series.items,
                fields = me.fields,
                ln = fields.length,
                min = isNaN(me.minimum) ? Infinity : me.minimum,
                max = isNaN(me.maximum) ? -Infinity : me.maximum,
                prevMin = me.prevMin,
                prevMax = me.prevMax,
                aggregate = false,
                total = 0,
                excludes = [],
                outfrom, outto,
                i, l, values, rec, out;

            //if one series is stacked I have to aggregate the values
            //for the scale.
            for (i = 0, l = series.length; !aggregate && i < l; i++) {
                aggregate = aggregate || series[i].stacked;
                excludes = series[i].__excludes || excludes;
            }
            store.each(function(record) {
                if (aggregate) {
                    if (!isFinite(min)) {
                        min = 0;
                    }
                    for (values = [0, 0], i = 0; i < ln; i++) {
                        if (excludes[i]) {
                            continue;
                        }
                        rec = record.get(fields[i]);
                        values[+(rec > 0)] += math.abs(rec);
                    }
                    max = mmax(max, -values[0], values[1]);
                    min = mmin(min, -values[0], values[1]);
                }
                else {
                    for (i = 0; i < ln; i++) {
                        if (excludes[i]) {
                            continue;
                        }
                        value = record.get(fields[i]);
                        max = mmax(max, value);
                        min = mmin(min, value);
                    }
                }
            });
            if (!isFinite(max)) {
                max = me.prevMax || 0;
            }
            if (!isFinite(min)) {
                min = me.prevMin || 0;
            }
            //normalize min max for snapEnds.
            if (min != max && (max != (max >> 0))) {
                max = (max >> 0) + 1;
            }
            out = Ext.draw.Draw.snapEnds(min, max, me.majorTickSteps !== false ?  (me.majorTickSteps +1) : me.steps);
            outfrom = out.from;
            outto = out.to;
            if (!isNaN(me.maximum)) {
                //TODO(nico) users are responsible for their own minimum/maximum values set.
                //Clipping should be added to remove lines in the chart which are below the axis.
                out.to = me.maximum;
            }
            if (!isNaN(me.minimum)) {
                //TODO(nico) users are responsible for their own minimum/maximum values set.
                //Clipping should be added to remove lines in the chart which are below the axis.
                out.from = me.minimum;
            }

            //Adjust after adjusting minimum and maximum
            out.step = (out.to - out.from) / (outto - outfrom) * out.step;

            if (me.adjustMaximumByMajorUnit) {
                out.to += out.step;
            }
            if (me.adjustMinimumByMajorUnit) {
                out.from -= out.step;
            }
            me.prevMin = min == max? 0 : min;
            me.prevMax = max;
            return out;
        },

        /**
         * Renders the axis into the screen and updates it's position.
         */
        drawAxis: function (init) {
            var me = this,
                i, j,
                x = me.x,
                y = me.y,
                gutterX = me.chart.maxGutter[0],
                gutterY = me.chart.maxGutter[1],
                dashSize = me.dashSize,
                subDashesX = me.minorTickSteps || 0,
                subDashesY = me.minorTickSteps || 0,
                length = me.length,
                position = me.position,
                inflections = [],
                calcLabels = false,
                stepCalcs = me.applyData(),
                step = stepCalcs.step,
                steps = stepCalcs.steps,
                from = stepCalcs.from,
                to = stepCalcs.to,
                trueLength,
                currentX,
                currentY,
                path,
                prev,
                dashesX,
                dashesY,
                delta;

            //If no steps are specified
            //then don't draw the axis. This generally happens
            //when an empty store.
            if (me.hidden || isNaN(step) || (from == to)) {
                return;
            }

            me.from = stepCalcs.from;
            me.to = stepCalcs.to;
            if (position == 'left' || position == 'right') {
                currentX = Math.floor(x) + 0.5;
                path = ["M", currentX, y, "l", 0, -length];
                trueLength = length - (gutterY * 2);
            }
            else {
                currentY = Math.floor(y) + 0.5;
                path = ["M", x, currentY, "l", length, 0];
                trueLength = length - (gutterX * 2);
            }

            delta = trueLength / (steps || 1);
            dashesX = Math.max(subDashesX +1, 0);
            dashesY = Math.max(subDashesY +1, 0);
            if (me.type == 'Numeric') {
                calcLabels = true;
                me.labels = [stepCalcs.from];
            }
            if (position == 'right' || position == 'left') {
                currentY = y - gutterY;
                currentX = x - ((position == 'left') * dashSize * 2);
                while (currentY >= y - gutterY - trueLength) {
                    path.push("M", currentX, Math.floor(currentY) + 0.5, "l", dashSize * 2 + 1, 0);
                    if (currentY != y - gutterY) {
                        for (i = 1; i < dashesY; i++) {
                            path.push("M", currentX + dashSize, Math.floor(currentY + delta * i / dashesY) + 0.5, "l", dashSize + 1, 0);
                        }
                    }
                    inflections.push([ Math.floor(x), Math.floor(currentY) ]);
                    currentY -= delta;
                    if (calcLabels) {
                        me.labels.push(me.labels[me.labels.length -1] + step);
                    }
                    if (delta === 0) {
                        break;
                    }
                }
                if (Math.round(currentY + delta - (y - gutterY - trueLength))) {
                    path.push("M", currentX, Math.floor(y - length + gutterY) + 0.5, "l", dashSize * 2 + 1, 0);
                    for (i = 1; i < dashesY; i++) {
                        path.push("M", currentX + dashSize, Math.floor(y - length + gutterY + delta * i / dashesY) + 0.5, "l", dashSize + 1, 0);
                    }
                    inflections.push([ Math.floor(x), Math.floor(currentY) ]);
                    if (calcLabels) {
                        me.labels.push(me.labels[me.labels.length -1] + step);
                    }
                }
            } else {
                currentX = x + gutterX;
                currentY = y - ((position == 'top') * dashSize * 2);
                while (currentX <= x + gutterX + trueLength) {
                    path.push("M", Math.floor(currentX) + 0.5, currentY, "l", 0, dashSize * 2 + 1);
                    if (currentX != x + gutterX) {
                        for (i = 1; i < dashesX; i++) {
                            path.push("M", Math.floor(currentX - delta * i / dashesX) + 0.5, currentY, "l", 0, dashSize + 1);
                        }
                    }
                    inflections.push([ Math.floor(currentX), Math.floor(y) ]);
                    currentX += delta;
                    if (calcLabels) {
                        me.labels.push(me.labels[me.labels.length -1] + step);
                    }
                    if (delta === 0) {
                        break;
                    }
                }
                if (Math.round(currentX - delta - (x + gutterX + trueLength))) {
                    path.push("M", Math.floor(x + length - gutterX) + 0.5, currentY, "l", 0, dashSize * 2 + 1);
                    for (i = 1; i < dashesX; i++) {
                        path.push("M", Math.floor(x + length - gutterX - delta * i / dashesX) + 0.5, currentY, "l", 0, dashSize + 1);
                    }
                    inflections.push([ Math.floor(currentX), Math.floor(y) ]);
                    if (calcLabels) {
                        me.labels.push(me.labels[me.labels.length -1] + step);
                    }
                }
            }
            if (!me.axis) {
                me.axis = me.chart.surface.add(Ext.apply({
                    type: 'path',
                    path: path
                }, me.axisStyle));
            }
            me.axis.setAttributes({
                path: path
            }, true);
            me.inflections = inflections;
            if (!init && me.grid) {
                me.drawGrid();
            }
            me.axisBBox = me.axis.getBBox();
            me.drawLabel();
        },

        /**
         * Renders an horizontal and/or vertical grid into the Surface.
         */
        drawGrid: function() {
            var me = this,
                surface = me.chart.surface,
                grid = me.grid,
                odd = grid.odd,
                even = grid.even,
                inflections = me.inflections,
                ln = inflections.length - ((odd || even)? 0 : 1),
                position = me.position,
                gutter = me.chart.maxGutter,
                width = me.width - 2,
                vert = false,
                point, prevPoint,
                i = 1,
                path = [], styles, lineWidth, dlineWidth,
                oddPath = [], evenPath = [];

            if ((gutter[1] !== 0 && (position == 'left' || position == 'right')) ||
                (gutter[0] !== 0 && (position == 'top' || position == 'bottom'))) {
                i = 0;
                ln++;
            }
            for (; i < ln; i++) {
                point = inflections[i];
                prevPoint = inflections[i - 1];
                if (odd || even) {
                    path = (i % 2)? oddPath : evenPath;
                    styles = ((i % 2)? odd : even) || {};
                    lineWidth = (styles.lineWidth || styles['stroke-width'] || 0) / 2;
                    dlineWidth = 2 * lineWidth;
                    if (position == 'left') {
                        path.push("M", prevPoint[0] + 1 + lineWidth, prevPoint[1] + 0.5 - lineWidth,
                                  "L", prevPoint[0] + 1 + width - lineWidth, prevPoint[1] + 0.5 - lineWidth,
                                  "L", point[0] + 1 + width - lineWidth, point[1] + 0.5 + lineWidth,
                                  "L", point[0] + 1 + lineWidth, point[1] + 0.5 + lineWidth, "Z");
                    }
                    else if (position == 'right') {
                        path.push("M", prevPoint[0] - lineWidth, prevPoint[1] + 0.5 - lineWidth,
                                  "L", prevPoint[0] - width + lineWidth, prevPoint[1] + 0.5 - lineWidth,
                                  "L", point[0] - width + lineWidth, point[1] + 0.5 + lineWidth,
                                  "L", point[0] - lineWidth, point[1] + 0.5 + lineWidth, "Z");
                    }
                    else if (position == 'top') {
                        path.push("M", prevPoint[0] + 0.5 + lineWidth, prevPoint[1] + 1 + lineWidth,
                                  "L", prevPoint[0] + 0.5 + lineWidth, prevPoint[1] + 1 + width - lineWidth,
                                  "L", point[0] + 0.5 - lineWidth, point[1] + 1 + width - lineWidth,
                                  "L", point[0] + 0.5 - lineWidth, point[1] + 1 + lineWidth, "Z");
                    }
                    else {
                        path.push("M", prevPoint[0] + 0.5 + lineWidth, prevPoint[1] - lineWidth,
                                "L", prevPoint[0] + 0.5 + lineWidth, prevPoint[1] - width + lineWidth,
                                "L", point[0] + 0.5 - lineWidth, point[1] - width + lineWidth,
                                "L", point[0] + 0.5 - lineWidth, point[1] - lineWidth, "Z");
                    }
                } else {
                    if (position == 'left') {
                        path = path.concat(["M", point[0] + 0.5, point[1] + 0.5, "l", width, 0]);
                    }
                    else if (position == 'right') {
                        path = path.concat(["M", point[0] - 0.5, point[1] + 0.5, "l", -width, 0]);
                    }
                    else if (position == 'top') {
                        path = path.concat(["M", point[0] + 0.5, point[1] + 0.5, "l", 0, width]);
                    }
                    else {
                        path = path.concat(["M", point[0] + 0.5, point[1] - 0.5, "l", 0, -width]);
                    }
                }
            }
            if (odd || even) {
                if (oddPath.length) {
                    if (!me.gridOdd && oddPath.length) {
                        me.gridOdd = surface.add({
                            type: 'path',
                            path: oddPath
                        });
                    }
                    me.gridOdd.setAttributes(Ext.apply({
                        path: oddPath,
                        hidden: false
                    }, odd || {}), true);
                }
                if (evenPath.length) {
                    if (!me.gridEven) {
                        me.gridEven = surface.add({
                            type: 'path',
                            path: evenPath
                        });
                    }
                    me.gridEven.setAttributes(Ext.apply({
                        path: evenPath,
                        hidden: false
                    }, even || {}), true);
                }
            }
            else {
                if (path.length) {
                    if (!me.gridLines) {
                        me.gridLines = me.chart.surface.add({
                            type: 'path',
                            path: path,
                            "stroke-width": me.lineWidth || 1,
                            stroke: me.gridColor || '#ccc'
                        });
                    }
                    me.gridLines.setAttributes({
                        hidden: false,
                        path: path
                    }, true);
                }
                else if (me.gridLines) {
                    me.gridLines.hide(true);
                }
            }
        },

        //@private
        getOrCreateLabel: function(i, text) {
            var me = this,
                labelGroup = me.labelGroup,
                textLabel = labelGroup.getAt(i),
                surface = me.chart.surface;
            if (textLabel) {
                if (text != textLabel.attr.text) {
                    textLabel.setAttributes(Ext.apply({
                        text: text
                    }, me.label), true);
                    textLabel._bbox = textLabel.getBBox();
                }
            }
            else {
                textLabel = surface.add(Ext.apply({
                    group: labelGroup,
                    type: 'text',
                    x: 0,
                    y: 0,
                    text: text
                }, me.label));
                surface.renderItem(textLabel);
                textLabel._bbox = textLabel.getBBox();
            }
            //get untransformed bounding box
            if (me.label.rotation) {
                textLabel.setAttributes({
                    rotation: {
                        degrees: 0
                    }
                }, true);
                textLabel._ubbox = textLabel.getBBox();
                textLabel.setAttributes(me.label, true);
            } else {
                textLabel._ubbox = textLabel._bbox;
            }
            return textLabel;
        },

        rect2pointArray: function(sprite) {
            var surface = this.chart.surface,
                rect = surface.getBBox(sprite, true),
                p1 = [rect.x, rect.y],
                p1p = p1.slice(),
                p2 = [rect.x + rect.width, rect.y],
                p2p = p2.slice(),
                p3 = [rect.x + rect.width, rect.y + rect.height],
                p3p = p3.slice(),
                p4 = [rect.x, rect.y + rect.height],
                p4p = p4.slice(),
                matrix = sprite.matrix;
            //transform the points
            p1[0] = matrix.x.apply(matrix, p1p);
            p1[1] = matrix.y.apply(matrix, p1p);

            p2[0] = matrix.x.apply(matrix, p2p);
            p2[1] = matrix.y.apply(matrix, p2p);

            p3[0] = matrix.x.apply(matrix, p3p);
            p3[1] = matrix.y.apply(matrix, p3p);

            p4[0] = matrix.x.apply(matrix, p4p);
            p4[1] = matrix.y.apply(matrix, p4p);
            return [p1, p2, p3, p4];
        },

        intersect: function(l1, l2) {
            var r1 = this.rect2pointArray(l1),
                r2 = this.rect2pointArray(l2);
            return !!Ext.draw.Draw.intersect(r1, r2).length;
        },

        drawHorizontalLabels: function() {
           var  me = this,
                labelConf = me.label,
                floor = Math.floor,
                max = Math.max,
                axes = me.chart.axes,
                position = me.position,
                inflections = me.inflections,
                ln = inflections.length,
                labels = me.labels,
                labelGroup = me.labelGroup,
                maxHeight = 0,
                ratio,
                gutterY = me.chart.maxGutter[1],
                ubbox, bbox, point, prevX, prevLabel,
                projectedWidth = 0,
                textLabel, attr, textRight, text,
                label, last, x, y, i, firstLabel;

            last = ln - 1;
            //get a reference to the first text label dimensions
            point = inflections[0];
            firstLabel = me.getOrCreateLabel(0, me.label.renderer(labels[0]));
            ratio = Math.abs(Math.sin(labelConf.rotate && (labelConf.rotate.degrees * Math.PI / 180) || 0)) >> 0;

            for (i = 0; i < ln; i++) {
                point = inflections[i];
                text = me.label.renderer(labels[i]);
                textLabel = me.getOrCreateLabel(i, text);
                bbox = textLabel._bbox;
                maxHeight = max(maxHeight, bbox.height + me.dashSize + me.label.padding);
                x = floor(point[0] - (ratio? bbox.height : bbox.width) / 2);
                if (me.chart.maxGutter[0] == 0) {
                    if (i == 0 && axes.findIndex('position', 'left') == -1) {
                        x = point[0];
                    }
                    else if (i == last && axes.findIndex('position', 'right') == -1) {
                        x = point[0] - bbox.width;
                    }
                }
                if (position == 'top') {
                    y = point[1] - (me.dashSize * 2) - me.label.padding - (bbox.height / 2);
                }
                else {
                    y = point[1] + (me.dashSize * 2) + me.label.padding + (bbox.height / 2);
                }

                textLabel.setAttributes({
                    hidden: false,
                    x: x,
                    y: y
                }, true);

                // Skip label if there isn't available minimum space
                if (i != 0 && (me.intersect(textLabel, prevLabel)
                    || me.intersect(textLabel, firstLabel))) {
                    textLabel.hide(true);
                    continue;
                }

                prevLabel = textLabel;
            }

            return maxHeight;
        },

        drawVerticalLabels: function() {
            var me = this,
                inflections = me.inflections,
                position = me.position,
                ln = inflections.length,
                labels = me.labels,
                maxWidth = 0,
                max = Math.max,
                floor = Math.floor,
                ceil = Math.ceil,
                axes = me.chart.axes,
                gutterY = me.chart.maxGutter[1],
                ubbox, bbox, point, prevLabel,
                projectedWidth = 0,
                textLabel, attr, textRight, text,
                label, last, x, y, i;

            last = ln;
            for (i = 0; i < last; i++) {
                point = inflections[i];
                text = me.label.renderer(labels[i]);
                textLabel = me.getOrCreateLabel(i, text);
                bbox = textLabel._bbox;

                maxWidth = max(maxWidth, bbox.width + me.dashSize + me.label.padding);
                y = point[1];
                if (gutterY < bbox.height / 2) {
                    if (i == last - 1 && axes.findIndex('position', 'top') == -1) {
                        y = me.y - me.length + ceil(bbox.height / 2);
                    }
                    else if (i == 0 && axes.findIndex('position', 'bottom') == -1) {
                        y = me.y - floor(bbox.height / 2);
                    }
                }
                if (position == 'left') {
                    x = point[0] - bbox.width - me.dashSize - me.label.padding - 2;
                }
                else {
                    x = point[0] + me.dashSize + me.label.padding + 2;
                }
                textLabel.setAttributes(Ext.apply({
                    hidden: false,
                    x: x,
                    y: y
                }, me.label), true);
                // Skip label if there isn't available minimum space
                if (i != 0 && me.intersect(textLabel, prevLabel)) {
                    textLabel.hide(true);
                    continue;
                }
                prevLabel = textLabel;
            }

            return maxWidth;
        },

        /**
         * Renders the labels in the axes.
         */
        drawLabel: function() {
            var me = this,
                position = me.position,
                labelGroup = me.labelGroup,
                inflections = me.inflections,
                maxWidth = 0,
                maxHeight = 0,
                ln, i;

            if (position == 'left' || position == 'right') {
                maxWidth = me.drawVerticalLabels();
            } else {
                maxHeight = me.drawHorizontalLabels();
            }

            // Hide unused bars
            ln = labelGroup.getCount();
            i = inflections.length;
            for (; i < ln; i++) {
                labelGroup.getAt(i).hide(true);
            }

            me.bbox = {};
            Ext.apply(me.bbox, me.axisBBox);
            me.bbox.height = maxHeight;
            me.bbox.width = maxWidth;
            if (Ext.isString(me.title)) {
                me.drawTitle(maxWidth, maxHeight);
            }
        },

        // @private creates the elipsis for the text.
        elipsis: function(sprite, text, desiredWidth, minWidth, center) {
            var bbox,
                x;

            if (desiredWidth < minWidth) {
                sprite.hide(true);
                return false;
            }
            while (text.length > 4) {
                text = text.substr(0, text.length - 4) + "...";
                sprite.setAttributes({
                    text: text
                }, true);
                bbox = sprite.getBBox();
                if (bbox.width < desiredWidth) {
                    if (typeof center == 'number') {
                        sprite.setAttributes({
                            x: Math.floor(center - (bbox.width / 2))
                        }, true);
                    }
                    break;
                }
            }
            return true;
        },

        /**
         * Updates the {@link #title} of this axis.
         * @param {String} title
         */
        setTitle: function(title) {
            this.title = title;
            this.drawLabel();
        },

        // @private draws the title for the axis.
        drawTitle: function(maxWidth, maxHeight) {
            var me = this,
                position = me.position,
                surface = me.chart.surface,
                displaySprite = me.displaySprite,
                title = me.title,
                rotate = (position == 'left' || position == 'right'),
                x = me.x,
                y = me.y,
                base, bbox, pad;

            if (displaySprite) {
                displaySprite.setAttributes({text: title}, true);
            } else {
                base = {
                    type: 'text',
                    x: 0,
                    y: 0,
                    text: title
                };
                displaySprite = me.displaySprite = surface.add(Ext.apply(base, me.axisTitleStyle, me.labelTitle));
                surface.renderItem(displaySprite);
            }
            bbox = displaySprite.getBBox();
            pad = me.dashSize + me.label.padding;

            if (rotate) {
                y -= ((me.length / 2) - (bbox.height / 2));
                if (position == 'left') {
                    x -= (maxWidth + pad + (bbox.width / 2));
                }
                else {
                    x += (maxWidth + pad + bbox.width - (bbox.width / 2));
                }
                me.bbox.width += bbox.width + 10;
            }
            else {
                x += (me.length / 2) - (bbox.width * 0.5);
                if (position == 'top') {
                    y -= (maxHeight + pad + (bbox.height * 0.3));
                }
                else {
                    y += (maxHeight + pad + (bbox.height * 0.8));
                }
                me.bbox.height += bbox.height + 10;
            }
            displaySprite.setAttributes({
                translate: {
                    x: x,
                    y: y
                }
            }, true);
        }
    });