"use strict";
module.exports = function(Chart) {
var helpers = Chart.helpers;
// The layout service is very self explanatory. It's responsible for the layout within a chart.
// Scales, Legends and Plugins all rely on the layout service and can easily register to be placed anywhere they need
// It is this service's responsibility of carrying out that layout.
Chart.layoutService = {
defaults: {},
// Register a box to a chartInstance. A box is simply a reference to an object that requires layout. eg. Scales, Legend, Plugins.
addBox: function(chartInstance, box) {
if (!chartInstance.boxes) {
chartInstance.boxes = [];
}
chartInstance.boxes.push(box);
},
removeBox: function(chartInstance, box) {
if (!chartInstance.boxes) {
return;
}
chartInstance.boxes.splice(chartInstance.boxes.indexOf(box), 1);
},
// The most important function
update: function(chartInstance, width, height) {
if (!chartInstance) {
return;
}
var xPadding = 0;
var yPadding = 0;
var leftBoxes = helpers.where(chartInstance.boxes, function(box) {
return box.options.position === "left";
});
var rightBoxes = helpers.where(chartInstance.boxes, function(box) {
return box.options.position === "right";
});
var topBoxes = helpers.where(chartInstance.boxes, function(box) {
return box.options.position === "top";
});
var bottomBoxes = helpers.where(chartInstance.boxes, function(box) {
return box.options.position === "bottom";
});
// Boxes that overlay the chartarea such as the radialLinear scale
var chartAreaBoxes = helpers.where(chartInstance.boxes, function(box) {
return box.options.position === "chartArea";
});
// Ensure that full width boxes are at the very top / bottom
topBoxes.sort(function(a, b) {
return (b.options.fullWidth ? 1 : 0) - (a.options.fullWidth ? 1 : 0);
});
bottomBoxes.sort(function(a, b) {
return (a.options.fullWidth ? 1 : 0) - (b.options.fullWidth ? 1 : 0);
});
// Essentially we now have any number of boxes on each of the 4 sides.
// Our canvas looks like the following.
// The areas L1 and L2 are the left axes. R1 is the right axis, T1 is the top axis and
// B1 is the bottom axis
// There are also 4 quadrant-like locations (left to right instead of clockwise) reserved for chart overlays
// These locations are single-box locations only, when trying to register a chartArea location that is already taken,
// an error will be thrown.
//
// |----------------------------------------------------|
// | T1 (Full Width) |
// |----------------------------------------------------|
// | | | T2 | |
// | |----|-------------------------------------|----|
// | | | C1 | | C2 | |
// | | |----| |----| |
// | | | | |
// | L1 | L2 | ChartArea (C0) | R1 |
// | | | | |
// | | |----| |----| |
// | | | C3 | | C4 | |
// | |----|-------------------------------------|----|
// | | | B1 | |
// |----------------------------------------------------|
// | B2 (Full Width) |
// |----------------------------------------------------|
//
// What we do to find the best sizing, we do the following
// 1. Determine the minimum size of the chart area.
// 2. Split the remaining width equally between each vertical axis
// 3. Split the remaining height equally between each horizontal axis
// 4. Give each layout the maximum size it can be. The layout will return it's minimum size
// 5. Adjust the sizes of each axis based on it's minimum reported size.
// 6. Refit each axis
// 7. Position each axis in the final location
// 8. Tell the chart the final location of the chart area
// 9. Tell any axes that overlay the chart area the positions of the chart area
// Step 1
var chartWidth = width - (2 * xPadding);
var chartHeight = height - (2 * yPadding);
var chartAreaWidth = chartWidth / 2; // min 50%
var chartAreaHeight = chartHeight / 2; // min 50%
// Step 2
var verticalBoxWidth = (width - chartAreaWidth) / (leftBoxes.length + rightBoxes.length);
// Step 3
var horizontalBoxHeight = (height - chartAreaHeight) / (topBoxes.length + bottomBoxes.length);
// Step 4
var maxChartAreaWidth = chartWidth;
var maxChartAreaHeight = chartHeight;
var minBoxSizes = [];
helpers.each(leftBoxes.concat(rightBoxes, topBoxes, bottomBoxes), getMinimumBoxSize);
function getMinimumBoxSize(box) {
var minSize;
var isHorizontal = box.isHorizontal();
if (isHorizontal) {
minSize = box.update(box.options.fullWidth ? chartWidth : maxChartAreaWidth, horizontalBoxHeight);
maxChartAreaHeight -= minSize.height;
} else {
minSize = box.update(verticalBoxWidth, chartAreaHeight);
maxChartAreaWidth -= minSize.width;
}
minBoxSizes.push({
horizontal: isHorizontal,
minSize: minSize,
box: box
});
}
// At this point, maxChartAreaHeight and maxChartAreaWidth are the size the chart area could
// be if the axes are drawn at their minimum sizes.
// Steps 5 & 6
var totalLeftBoxesWidth = xPadding;
var totalRightBoxesWidth = xPadding;
var totalTopBoxesHeight = yPadding;
var totalBottomBoxesHeight = yPadding;
// Update, and calculate the left and right margins for the horizontal boxes
helpers.each(leftBoxes.concat(rightBoxes), fitBox);
helpers.each(leftBoxes, function(box) {
totalLeftBoxesWidth += box.width;
});
helpers.each(rightBoxes, function(box) {
totalRightBoxesWidth += box.width;
});
// Set the Left and Right margins for the horizontal boxes
helpers.each(topBoxes.concat(bottomBoxes), fitBox);
// Function to fit a box
function fitBox(box) {
var minBoxSize = helpers.findNextWhere(minBoxSizes, function(minBoxSize) {
return minBoxSize.box === box;
});
if (minBoxSize) {
if (box.isHorizontal()) {
var scaleMargin = {
left: totalLeftBoxesWidth,
right: totalRightBoxesWidth,
top: 0,
bottom: 0
};
// Don't use min size here because of label rotation. When the labels are rotated, their rotation highly depends
// on the margin. Sometimes they need to increase in size slightly
box.update(box.options.fullWidth ? chartWidth : maxChartAreaWidth, chartHeight / 2, scaleMargin);
} else {
box.update(minBoxSize.minSize.width, maxChartAreaHeight);
}
}
}
// Figure out how much margin is on the top and bottom of the vertical boxes
helpers.each(topBoxes, function(box) {
totalTopBoxesHeight += box.height;
});
helpers.each(bottomBoxes, function(box) {
totalBottomBoxesHeight += box.height;
});
// Let the left layout know the final margin
helpers.each(leftBoxes.concat(rightBoxes), finalFitVerticalBox);
function finalFitVerticalBox(box) {
var minBoxSize = helpers.findNextWhere(minBoxSizes, function(minBoxSize) {
return minBoxSize.box === box;
});
var scaleMargin = {
left: 0,
right: 0,
top: totalTopBoxesHeight,
bottom: totalBottomBoxesHeight
};
if (minBoxSize) {
box.update(minBoxSize.minSize.width, maxChartAreaHeight, scaleMargin);
}
}
// Recalculate because the size of each layout might have changed slightly due to the margins (label rotation for instance)
totalLeftBoxesWidth = xPadding;
totalRightBoxesWidth = xPadding;
totalTopBoxesHeight = yPadding;
totalBottomBoxesHeight = yPadding;
helpers.each(leftBoxes, function(box) {
totalLeftBoxesWidth += box.width;
});
helpers.each(rightBoxes, function(box) {
totalRightBoxesWidth += box.width;
});
helpers.each(topBoxes, function(box) {
totalTopBoxesHeight += box.height;
});
helpers.each(bottomBoxes, function(box) {
totalBottomBoxesHeight += box.height;
});
// Figure out if our chart area changed. This would occur if the dataset layout label rotation
// changed due to the application of the margins in step 6. Since we can only get bigger, this is safe to do
// without calling `fit` again
var newMaxChartAreaHeight = height - totalTopBoxesHeight - totalBottomBoxesHeight;
var newMaxChartAreaWidth = width - totalLeftBoxesWidth - totalRightBoxesWidth;
if (newMaxChartAreaWidth !== maxChartAreaWidth || newMaxChartAreaHeight !== maxChartAreaHeight) {
helpers.each(leftBoxes, function(box) {
box.height = newMaxChartAreaHeight;
});
helpers.each(rightBoxes, function(box) {
box.height = newMaxChartAreaHeight;
});
helpers.each(topBoxes, function(box) {
if (!box.options.fullWidth) {
box.width = newMaxChartAreaWidth;
}
});
helpers.each(bottomBoxes, function(box) {
if (!box.options.fullWidth) {
box.width = newMaxChartAreaWidth;
}
});
maxChartAreaHeight = newMaxChartAreaHeight;
maxChartAreaWidth = newMaxChartAreaWidth;
}
// Step 7 - Position the boxes
var left = xPadding;
var top = yPadding;
var right = 0;
var bottom = 0;
helpers.each(leftBoxes.concat(topBoxes), placeBox);
// Account for chart width and height
left += maxChartAreaWidth;
top += maxChartAreaHeight;
helpers.each(rightBoxes, placeBox);
helpers.each(bottomBoxes, placeBox);
function placeBox(box) {
if (box.isHorizontal()) {
box.left = box.options.fullWidth ? xPadding : totalLeftBoxesWidth;
box.right = box.options.fullWidth ? width - xPadding : totalLeftBoxesWidth + maxChartAreaWidth;
box.top = top;
box.bottom = top + box.height;
// Move to next point
top = box.bottom;
} else {
box.left = left;
box.right = left + box.width;
box.top = totalTopBoxesHeight;
box.bottom = totalTopBoxesHeight + maxChartAreaHeight;
// Move to next point
left = box.right;
}
}
// Step 8
chartInstance.chartArea = {
left: totalLeftBoxesWidth,
top: totalTopBoxesHeight,
right: totalLeftBoxesWidth + maxChartAreaWidth,
bottom: totalTopBoxesHeight + maxChartAreaHeight
};
// Step 9
helpers.each(chartAreaBoxes, function(box) {
box.left = chartInstance.chartArea.left;
box.top = chartInstance.chartArea.top;
box.right = chartInstance.chartArea.right;
box.bottom = chartInstance.chartArea.bottom;
box.update(maxChartAreaWidth, maxChartAreaHeight);
});
}
};
};
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