From cb55e4811f591b3db7f85519d500b4a0cfd88bf5 Mon Sep 17 00:00:00 2001
From: Kore Nordmann <github@kore-nordmann.de>
Date: Thu, 8 Jun 2006 13:17:08 +0000
Subject: - Handle Much data points with labeled axis

---
 src/axis/labeled.php        | 43 ++++++++++++++++++++++++++++++++++----
 tests/labeled_axis_test.php | 51 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+), 4 deletions(-)

diff --git a/src/axis/labeled.php b/src/axis/labeled.php
index b6e0960..5a4f742 100644
--- a/src/axis/labeled.php
+++ b/src/axis/labeled.php
@@ -22,6 +22,19 @@ class ezcGraphChartElementLabeledAxis extends ezcGraphChartElementAxis
      */
     protected $labels = array();
 
+    /**
+     * Reduced amount of labels which will be displayed in the chart
+     * 
+     * @var array
+     */
+    protected $displayedLabels = array();
+
+    /**
+     * Maximum count of labels which can be displayed on one axis
+     * @TODO: Perhaps base this on the chart size
+     */
+    const MAX_LABEL_COUNT = 10;
+
     protected function increaseKeys( $array, $startKey )
     {
         foreach ( $array as $key => $value )
@@ -85,7 +98,29 @@ class ezcGraphChartElementLabeledAxis extends ezcGraphChartElementAxis
      */
     public function calculateAxisBoundings()
     {
-        return true;
+        $labelCount = count( $this->labels ) - 1;
+        if ( $labelCount <= self::MAX_LABEL_COUNT )
+        {
+            $this->displayedLabels = $this->labels;
+            return true;
+        }
+
+        for ( $div = self::MAX_LABEL_COUNT; $div > 0; --$div )
+        {
+            if ( ( $labelCount % $div ) === 0 )
+            {
+                $step = $labelCount / $div;
+                foreach ( $this->labels as $nr => $label )
+                {
+                    if ( ( $nr % $step ) === 0 )
+                    {
+                        $this->displayedLabels[] = $label;
+                    }
+                }
+
+                return true;
+            }
+        }
     }
 
     /**
@@ -158,7 +193,7 @@ class ezcGraphChartElementLabeledAxis extends ezcGraphChartElementAxis
      */
     protected function getMajorStepCount()
     {
-        return count( $this->labels ) - 1;
+        return count( $this->displayedLabels ) - 1;
     }
 
     /**
@@ -301,9 +336,9 @@ class ezcGraphChartElementLabeledAxis extends ezcGraphChartElementAxis
      */
     protected function getLabel( $step )
     {
-        if ( isset( $this->labels[$step] ) )
+        if ( isset( $this->displayedLabels[$step] ) )
         {
-            return $this->labels[$step];
+            return $this->displayedLabels[$step];
         }
         else
         {
diff --git a/tests/labeled_axis_test.php b/tests/labeled_axis_test.php
index 009c3e7..767cbe3 100644
--- a/tests/labeled_axis_test.php
+++ b/tests/labeled_axis_test.php
@@ -448,6 +448,57 @@ class ezcGraphLabeledAxisTest extends ezcTestCase
 
         $chart->render( 500, 200 );
     }
+
+    public function testRenderLabeledAxisWithManyPoints()
+    {
+        $data = array();
+        for ( $i = -100; $i <= 500; ++$i )
+        {
+            $data[$i] = 25 * sin( $i / 50 );
+        }
+        $chart = ezcGraph::create( 'Line' );
+        $chart->sinus = $data;
+
+        $mockedRenderer = $this->getMock( 'ezcGraphRenderer2D', array(
+            'drawTextBox',
+        ) );
+
+        // X-Axis
+        $mockedRenderer
+            ->expects( $this->at( 1 ) )
+            ->method( 'drawTextBox' )
+            ->with(
+                $this->equalTo( new ezcGraphCoordinate( 122, 102 ) ),
+                $this->equalTo( '-100' ),
+                $this->equalTo( 31 ),
+                $this->equalTo( 8 ),
+                $this->equalTo( ezcGraph::LEFT | ezcGraph::TOP )
+            );
+        $mockedRenderer
+            ->expects( $this->at( 2 ) )
+            ->method( 'drawTextBox' )
+            ->with(
+                $this->equalTo( new ezcGraphCoordinate( 155, 102 ) ),
+                $this->equalTo( '-40' ),
+                $this->equalTo( 31 ),
+                $this->equalTo( 8 ),
+                $this->equalTo( ezcGraph::CENTER | ezcGraph::TOP )
+            );
+        $mockedRenderer
+            ->expects( $this->at( 11 ) )
+            ->method( 'drawTextBox' )
+            ->with(
+                $this->equalTo( new ezcGraphCoordinate( 450, 102 ) ),
+                $this->equalTo( '500' ),
+                $this->equalTo( 31 ),
+                $this->equalTo( 8 ),
+                $this->equalTo( ezcGraph::RIGHT | ezcGraph::TOP )
+            );
+
+        $chart->renderer = $mockedRenderer;
+
+        $chart->render( 500, 200 );
+    }
 }
 
 ?>
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