Subversion Repositories SmartDukaan

/*

Flot plugin for selecting regions.

The plugin defines the following options:

  selection: {

    mode: null or "x" or "y" or "xy",

    color: color

  }

Selection support is enabled by setting the mode to one of "x", "y" or

"xy". In "x" mode, the user will only be able to specify the x range,

similarly for "y" mode. For "xy", the selection becomes a rectangle

where both ranges can be specified. "color" is color of the selection

(if you need to change the color later on, you can get to it with

plot.getOptions().selection.color).

When selection support is enabled, a "plotselected" event will be

emitted on the DOM element you passed into the plot function. The

event handler gets a parameter with the ranges selected on the axes,

like this:

  placeholder.bind("plotselected", function(event, ranges) {

    alert("You selected " + ranges.xaxis.from + " to " + ranges.xaxis.to)

    // similar for yaxis - with multiple axes, the extra ones are in

    // x2axis, x3axis, ...

  });

The "plotselected" event is only fired when the user has finished

making the selection. A "plotselecting" event is fired during the

process with the same parameters as the "plotselected" event, in case

you want to know what's happening while it's happening,

A "plotunselected" event with no arguments is emitted when the user

clicks the mouse to remove the selection.

The plugin allso adds the following methods to the plot object:

- setSelection(ranges, preventEvent)

  Set the selection rectangle. The passed in ranges is on the same

  form as returned in the "plotselected" event. If the selection mode

  is "x", you should put in either an xaxis range, if the mode is "y"

  you need to put in an yaxis range and both xaxis and yaxis if the

  selection mode is "xy", like this:

    setSelection({ xaxis: { from: 0, to: 10 }, yaxis: { from: 40, to: 60 } });

  setSelection will trigger the "plotselected" event when called. If

  you don't want that to happen, e.g. if you're inside a

  "plotselected" handler, pass true as the second parameter. If you

  are using multiple axes, you can specify the ranges on any of those,

  e.g. as x2axis/x3axis/... instead of xaxis, the plugin picks the

  first one it sees.

- clearSelection(preventEvent)

  Clear the selection rectangle. Pass in true to avoid getting a

  "plotunselected" event.

- getSelection()

  Returns the current selection in the same format as the

  "plotselected" event. If there's currently no selection, the

  function returns null.

*/

(function ($) {

    function init(plot) {

        var selection = {

                first: { x: -1, y: -1}, second: { x: -1, y: -1},

                show: false,

                active: false

            };

        // FIXME: The drag handling implemented here should be

        // abstracted out, there's some similar code from a library in

        // the navigation plugin, this should be massaged a bit to fit

        // the Flot cases here better and reused. Doing this would

        // make this plugin much slimmer.

        var savedhandlers = {};

        var mouseUpHandler = null;

        function onMouseMove(e) {

            if (selection.active) {

                updateSelection(e);

                plot.getPlaceholder().trigger("plotselecting", [ getSelection() ]);

            }

        }

        function onMouseDown(e) {

            if (e.which != 1)  // only accept left-click

                return;

            // cancel out any text selections

            document.body.focus();

            // prevent text selection and drag in old-school browsers

            if (document.onselectstart !== undefined && savedhandlers.onselectstart == null) {

                savedhandlers.onselectstart = document.onselectstart;

                document.onselectstart = function () { return false; };

            }

            if (document.ondrag !== undefined && savedhandlers.ondrag == null) {

                savedhandlers.ondrag = document.ondrag;

                document.ondrag = function () { return false; };

            }

            setSelectionPos(selection.first, e);

            selection.active = true;

            // this is a bit silly, but we have to use a closure to be

            // able to whack the same handler again

            mouseUpHandler = function (e) { onMouseUp(e); };

            $(document).one("mouseup", mouseUpHandler);

        }

        function onMouseUp(e) {

            mouseUpHandler = null;

            // revert drag stuff for old-school browsers

            if (document.onselectstart !== undefined)

                document.onselectstart = savedhandlers.onselectstart;

            if (document.ondrag !== undefined)

                document.ondrag = savedhandlers.ondrag;

            // no more dragging

            selection.active = false;

            updateSelection(e);

            if (selectionIsSane())

                triggerSelectedEvent();

            else {

                // this counts as a clear

                plot.getPlaceholder().trigger("plotunselected", [ ]);

                plot.getPlaceholder().trigger("plotselecting", [ null ]);

            }

            return false;

        }

        function getSelection() {

            if (!selectionIsSane())

                return null;

            var r = {}, c1 = selection.first, c2 = selection.second;

            $.each(plot.getAxes(), function (name, axis) {

                if (axis.used) {

                    var p1 = axis.c2p(c1[axis.direction]), p2 = axis.c2p(c2[axis.direction]); 

                    r[name] = { from: Math.min(p1, p2), to: Math.max(p1, p2) };

                }

            });

            return r;

        }

        function triggerSelectedEvent() {

            var r = getSelection();

            plot.getPlaceholder().trigger("plotselected", [ r ]);

            // backwards-compat stuff, to be removed in future

            if (r.xaxis && r.yaxis)

                plot.getPlaceholder().trigger("selected", [ { x1: r.xaxis.from, y1: r.yaxis.from, x2: r.xaxis.to, y2: r.yaxis.to } ]);

        }

        function clamp(min, value, max) {

            return value < min ? min: (value > max ? max: value);

        }

        function setSelectionPos(pos, e) {

            var o = plot.getOptions();

            var offset = plot.getPlaceholder().offset();

            var plotOffset = plot.getPlotOffset();

            pos.x = clamp(0, e.pageX - offset.left - plotOffset.left, plot.width());

            pos.y = clamp(0, e.pageY - offset.top - plotOffset.top, plot.height());

            if (o.selection.mode == "y")

                pos.x = pos == selection.first ? 0 : plot.width();

            if (o.selection.mode == "x")

                pos.y = pos == selection.first ? 0 : plot.height();

        }

        function updateSelection(pos) {

            if (pos.pageX == null)

                return;

            setSelectionPos(selection.second, pos);

            if (selectionIsSane()) {

                selection.show = true;

                plot.triggerRedrawOverlay();

            }

            else

                clearSelection(true);

        }

        function clearSelection(preventEvent) {

            if (selection.show) {

                selection.show = false;

                plot.triggerRedrawOverlay();

                if (!preventEvent)

                    plot.getPlaceholder().trigger("plotunselected", [ ]);

            }

        }

        // function taken from markings support in Flot

        function extractRange(ranges, coord) {

            var axis, from, to, key, axes = plot.getAxes();

            for (var k in axes) {

                axis = axes[k];

                if (axis.direction == coord) {

                    key = coord + axis.n + "axis";

                    if (!ranges[key] && axis.n == 1)

                        key = coord + "axis"; // support x1axis as xaxis

                    if (ranges[key]) {

                        from = ranges[key].from;

                        to = ranges[key].to;

                        break;

                    }

                }

            }

            // backwards-compat stuff - to be removed in future

            if (!ranges[key]) {

                axis = coord == "x" ? plot.getXAxes()[0] : plot.getYAxes()[0];

                from = ranges[coord + "1"];

                to = ranges[coord + "2"];

            }

            // auto-reverse as an added bonus

            if (from != null && to != null && from > to) {

                var tmp = from;

                from = to;

                to = tmp;

            }

            return { from: from, to: to, axis: axis };

        }

        function setSelection(ranges, preventEvent) {

            var axis, range, o = plot.getOptions();

            if (o.selection.mode == "y") {

                selection.first.x = 0;

                selection.second.x = plot.width();

            }

            else {

                range = extractRange(ranges, "x");

                selection.first.x = range.axis.p2c(range.from);

                selection.second.x = range.axis.p2c(range.to);

            }

            if (o.selection.mode == "x") {

                selection.first.y = 0;

                selection.second.y = plot.height();

            }

            else {

                range = extractRange(ranges, "y");

                selection.first.y = range.axis.p2c(range.from);

                selection.second.y = range.axis.p2c(range.to);

            }

            selection.show = true;

            plot.triggerRedrawOverlay();

            if (!preventEvent && selectionIsSane())

                triggerSelectedEvent();

        }

        function selectionIsSane() {

            var minSize = 5;

            return Math.abs(selection.second.x - selection.first.x) >= minSize &&

                Math.abs(selection.second.y - selection.first.y) >= minSize;

        }

        plot.clearSelection = clearSelection;

        plot.setSelection = setSelection;

        plot.getSelection = getSelection;

        plot.hooks.bindEvents.push(function(plot, eventHolder) {

            var o = plot.getOptions();

            if (o.selection.mode != null) {

                eventHolder.mousemove(onMouseMove);

                eventHolder.mousedown(onMouseDown);

            }

        });

        plot.hooks.drawOverlay.push(function (plot, ctx) {

            // draw selection

            if (selection.show && selectionIsSane()) {

                var plotOffset = plot.getPlotOffset();

                var o = plot.getOptions();

                ctx.save();

                ctx.translate(plotOffset.left, plotOffset.top);

                var c = $.color.parse(o.selection.color);

                ctx.strokeStyle = c.scale('a', 0.8).toString();

                ctx.lineWidth = 1;

                ctx.lineJoin = "round";

                ctx.fillStyle = c.scale('a', 0.4).toString();

                var x = Math.min(selection.first.x, selection.second.x),

                    y = Math.min(selection.first.y, selection.second.y),

                    w = Math.abs(selection.second.x - selection.first.x),

                    h = Math.abs(selection.second.y - selection.first.y);

                ctx.fillRect(x, y, w, h);

                ctx.strokeRect(x, y, w, h);

                ctx.restore();

            }

        });

        plot.hooks.shutdown.push(function (plot, eventHolder) {

            eventHolder.unbind("mousemove", onMouseMove);

            eventHolder.unbind("mousedown", onMouseDown);

            if (mouseUpHandler)

                $(document).unbind("mouseup", mouseUpHandler);

        });

    }

    $.plot.plugins.push({

        init: init,

        options: {

            selection: {

                mode: null, // one of null, "x", "y" or "xy"

                color: "#e8cfac"

            }

        },

        name: 'selection',

        version: '1.1'

    });

})(jQuery);