Feature to allow forcing YAxis label-count

ChartsOrg · Jul 26, 2015 · edd9c2e · edd9c2e
1 parent d538322
commit edd9c2e
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Showing 3 changed files with 134 additions and 65 deletions.
diff --git a/Charts/Classes/Components/ChartYAxis.swift b/Charts/Classes/Components/ChartYAxis.swift
@@ -53,6 +53,9 @@ public class ChartYAxis: ChartAxisBase
     /// if true, the y-label entries will always start at zero
     public var startAtZeroEnabled = true
 
+    /// if true, the set number of y-labels will be forced
+    public var forceLabelsEnabled = true
+
     /// the formatter used to customly format the y-labels
     public var valueFormatter: NSNumberFormatter?
 
@@ -127,6 +130,22 @@ public class ChartYAxis: ChartAxisBase
         return _axisDependency
     }
 
+    public func setLabelCount(count: Int, force: Bool)
+    {
+        _labelCount = count
+
+        if (_labelCount > 25)
+        {
+            _labelCount = 25
+        }
+        if (_labelCount < 2)
+        {
+            _labelCount = 2
+        }
+
+        forceLabelsEnabled = force
+    }
+
     /// the number of label entries the y-axis should have
     /// max = 25,
     /// min = 2,
@@ -140,16 +159,7 @@ public class ChartYAxis: ChartAxisBase
         }
         set
         {
-            _labelCount = newValue
-
-            if (_labelCount > 25)
-            {
-                _labelCount = 25
-            }
-            if (_labelCount < 2)
-            {
-                _labelCount = 2
-            }
+            setLabelCount(newValue, force: false);
         }
     }
 
@@ -224,7 +234,10 @@ public class ChartYAxis: ChartAxisBase
     public var isInverted: Bool { return inverted; }
 
     public var isStartAtZeroEnabled: Bool { return startAtZeroEnabled; }
-
+
+    /// :returns: true if focing the y-label count is enabled. Default: false
+    public var isForceLabelsEnabled: Bool { return forceLabelsEnabled }
+
     public var isShowOnlyMinMaxEnabled: Bool { return showOnlyMinMaxEnabled; }
 
     public var isDrawTopYLabelEntryEnabled: Bool { return drawTopYLabelEntryEnabled; }

diff --git a/Charts/Classes/Renderers/ChartYAxisRenderer.swift b/Charts/Classes/Renderers/ChartYAxisRenderer.swift
@@ -78,37 +78,65 @@ public class ChartYAxisRenderer: ChartAxisRendererBase
             interval = floor(10.0 * intervalMagnitude)
         }
 
-        // if the labels should only show min and max
-        if (_yAxis.isShowOnlyMinMaxEnabled)
+        // force label count
+        if _yAxis.isForceLabelsEnabled
         {
-            _yAxis.entries = [yMin, yMax]
-        }
-        else
-        {
-            var first = ceil(Double(yMin) / interval) * interval
-            var last = ChartUtils.nextUp(floor(Double(yMax) / interval) * interval)
+            let step = Double(range) / Double(labelCount - 1)
 
-            var f: Double
-            var i: Int
-            var n = 0
-            for (f = first; f <= last; f += interval)
+            if _yAxis.entries.count < labelCount
             {
-                ++n
+                // Ensure stops contains at least numStops elements.
+                _yAxis.entries.removeAll(keepCapacity: true)
             }
-
-            if (_yAxis.entries.count < n)
+            else
             {
-                // Ensure stops contains at least numStops elements.
-                _yAxis.entries = [Double](count: n, repeatedValue: 0.0)
+                _yAxis.entries = [Double]()
+                _yAxis.entries.reserveCapacity(labelCount)
             }
-            else if (_yAxis.entries.count > n)
+
+            var v = yMin
+
+            for (var i = 0; i < labelCount; i++)
             {
-                _yAxis.entries.removeRange(n..<_yAxis.entries.count)
+                _yAxis.entries.append(v)
+                v += step
             }
 
-            for (f = first, i = 0; i < n; f += interval, ++i)
+        } else {
+            // no forced count
+
+            // if the labels should only show min and max
+            if (_yAxis.isShowOnlyMinMaxEnabled)
+            {
+                _yAxis.entries = [yMin, yMax]
+            }
+            else
             {
-                _yAxis.entries[i] = Double(f)
+                var first = ceil(Double(yMin) / interval) * interval
+                var last = ChartUtils.nextUp(floor(Double(yMax) / interval) * interval)
+
+                var f: Double
+                var i: Int
+                var n = 0
+                for (f = first; f <= last; f += interval)
+                {
+                    ++n
+                }
+
+                if (_yAxis.entries.count < n)
+                {
+                    // Ensure stops contains at least numStops elements.
+                    _yAxis.entries = [Double](count: n, repeatedValue: 0.0)
+                }
+                else if (_yAxis.entries.count > n)
+                {
+                    _yAxis.entries.removeRange(n..<_yAxis.entries.count)
+                }
+
+                for (f = first, i = 0; i < n; f += interval, ++i)
+                {
+                    _yAxis.entries[i] = Double(f)
+                }
             }
         }
     }

diff --git a/Charts/Classes/Renderers/ChartYAxisRendererRadarChart.swift b/Charts/Classes/Renderers/ChartYAxisRendererRadarChart.swift
@@ -54,52 +54,80 @@ public class ChartYAxisRendererRadarChart: ChartYAxisRenderer
             interval = floor(10 * intervalMagnitude)
         }
 
-        // clean old values
-        if (_yAxis.entries.count > 0)
+        // force label count
+        if _yAxis.isForceLabelsEnabled
         {
-            _yAxis.entries.removeAll(keepCapacity: false)
-        }
-
-        // if the labels should only show min and max
-        if (_yAxis.isShowOnlyMinMaxEnabled)
-        {
-            _yAxis.entries = [Double]()
-            _yAxis.entries.append(yMin)
-            _yAxis.entries.append(yMax)
-        }
-        else
-        {
-            var first = ceil(Double(yMin) / interval) * interval
+            let step = Double(range) / Double(labelCount - 1)
 
-            if (first == 0.0)
-            { // Fix for IEEE negative zero case (Where value == -0.0, and 0.0 == -0.0)
-                first = 0.0
+            if _yAxis.entries.count < labelCount
+            {
+                // Ensure stops contains at least numStops elements.
+                _yAxis.entries.removeAll(keepCapacity: true)
+            }
+            else
+            {
+                _yAxis.entries = [Double]()
+                _yAxis.entries.reserveCapacity(labelCount)
             }
 
-            var last = ChartUtils.nextUp(floor(Double(yMax) / interval) * interval)
+            var v = yMin
 
-            var f: Double
-            var i: Int
-            var n = 0
-            for (f = first; f <= last; f += interval)
+            for (var i = 0; i < labelCount; i++)
             {
-                ++n
+                _yAxis.entries.append(v)
+                v += step
             }
 
-            if (isnan(_yAxis.customAxisMax))
+        } else {
+            // no forced count
+
+            // clean old values
+            if (_yAxis.entries.count > 0)
             {
-                n += 1
+                _yAxis.entries.removeAll(keepCapacity: false)
             }
-
-            if (_yAxis.entries.count < n)
+
+            // if the labels should only show min and max
+            if (_yAxis.isShowOnlyMinMaxEnabled)
             {
-                // Ensure stops contains at least numStops elements.
-                _yAxis.entries = [Double](count: n, repeatedValue: 0.0)
+                _yAxis.entries = [Double]()
+                _yAxis.entries.append(yMin)
+                _yAxis.entries.append(yMax)
             }
-
-            for (f = first, i = 0; i < n; f += interval, ++i)
+            else
             {
-                _yAxis.entries[i] = Double(f)
+                var first = ceil(Double(yMin) / interval) * interval
+
+                if (first == 0.0)
+                { // Fix for IEEE negative zero case (Where value == -0.0, and 0.0 == -0.0)
+                    first = 0.0
+                }
+
+                var last = ChartUtils.nextUp(floor(Double(yMax) / interval) * interval)
+
+                var f: Double
+                var i: Int
+                var n = 0
+                for (f = first; f <= last; f += interval)
+                {
+                    ++n
+                }
+
+                if (isnan(_yAxis.customAxisMax))
+                {
+                    n += 1
+                }
+
+                if (_yAxis.entries.count < n)
+                {
+                    // Ensure stops contains at least numStops elements.
+                    _yAxis.entries = [Double](count: n, repeatedValue: 0.0)
+                }
+
+                for (f = first, i = 0; i < n; f += interval, ++i)
+                {
+                    _yAxis.entries[i] = Double(f)
+                }
             }
         }