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Brian Burg committed 1caf06b

add flot.selection.js

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  • Parent commits 30e410c

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File addon/lib/jquery.flot.selection.js

+/*
+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);