Rename calculateTickRotation to calculateLabelRotation (#6809)

Author: benmccann

docs/developers/axes.md

@@ -96,11 +96,11 @@ Optionally, the following methods may also be overwritten, but an implementation
 
 ```javascript
 {
-    // Transform the ticks array of the scale instance into strings. The default implementation simply calls this.options.ticks.callback(numericalTick, index, ticks);
-    convertTicksToLabels: function() {},
+    // Adds labels to objects in the ticks array. The default implementation simply calls this.options.ticks.callback(numericalTick, index, ticks);
+    generateTickLabels: function() {},
 
     // Determine how much the labels will rotate by. The default implementation will only rotate labels if the scale is horizontal.
-    calculateTickRotation: function() {},
+    calculateLabelRotation: function() {},
 
     // Fits the scale into the canvas.
     // this.maxWidth and this.maxHeight will tell you the maximum dimensions the scale instance can be. Scales should endeavour to be as efficient as possible with canvas space.

docs/getting-started/v3-migration.md

@@ -108,6 +108,7 @@ Chart.js 3.0 introduces a number of breaking changes. Chart.js 2.0 was released
 * `Chart.Animation.animationObject` was renamed to `Chart.Animation`
 * `Chart.Animation.chartInstance` was renamed to `Chart.Animation.chart`
 * `DatasetController.updateElement` was renamed to `DatasetController.updateElements`
+* `Scale.calculateTickRotation` was renamed to `Scale.calculateLabelRotation`
 * `TimeScale.getLabelCapacity` was renamed to `TimeScale._getLabelCapacity`
 * `TimeScale.tickFormatFunction` was renamed to `TimeScale._tickFormatFunction`
 * `TimeScale.getPixelForOffset` was renamed to `TimeScale._getPixelForOffset`

src/core/core.scale.js

@@ -477,17 +477,17 @@ class Scale extends Element {
 
 		// _configure is called twice, once here, once from core.controller.updateLayout.
 		// Here we haven't been positioned yet, but dimensions are correct.
-		// Variables set in _configure are needed for calculateTickRotation, and
+		// Variables set in _configure are needed for calculateLabelRotation, and
 		// it's ok that coordinates are not correct there, only dimensions matter.
 		me._configure();
 
 		// Tick Rotation
-		me.beforeCalculateTickRotation();
-		me.calculateTickRotation();
-		me.afterCalculateTickRotation();
+		me.beforeCalculateLabelRotation();
+		me.calculateLabelRotation(); // Preconditions: number of ticks and sizes of largest labels must be calculated beforehand
+		me.afterCalculateLabelRotation();
 
 		me.beforeFit();
-		me.fit();
+		me.fit(); // Preconditions: label rotation and label sizes must be calculated beforehand
 		me.afterFit();
 
 		// Auto-skip
@@ -604,10 +604,10 @@ class Scale extends Element {
 
 	//
 
-	beforeCalculateTickRotation() {
-		helpers.callback(this.options.beforeCalculateTickRotation, [this]);
+	beforeCalculateLabelRotation() {
+		helpers.callback(this.options.beforeCalculateLabelRotation, [this]);
 	}
-	calculateTickRotation() {
+	calculateLabelRotation() {
 		var me = this;
 		var options = me.options;
 		var tickOpts = options.ticks;
@@ -646,8 +646,8 @@ class Scale extends Element {
 
 		me.labelRotation = labelRotation;
 	}
-	afterCalculateTickRotation() {
-		helpers.callback(this.options.afterCalculateTickRotation, [this]);
+	afterCalculateLabelRotation() {
+		helpers.callback(this.options.afterCalculateLabelRotation, [this]);
 	}
 
 	//