- Refactored rotated axis label renderer for better extensibility

# Groundwork for #15095

1 files changed, 254 insertions, 197 deletions

diff --git a/src/renderer/axis_label_rotated.php b/src/renderer/axis_label_rotated.php
index 6187494..201cdb3 100644
--- a/src/renderer/axis_label_rotated.php
+++ b/src/renderer/axis_label_rotated.php
@@ -151,53 +151,23 @@ class ezcGraphAxisRotatedLabelRenderer extends ezcGraphAxisLabelRenderer
     }
 
     /**
-     * Render Axis labels
+     * Determine text offset.
      *
-     * Render labels for an axis.
+     * Calculate the label offset and angle, from the configured or evaluated
+     * text angle.
      *
-     * @param ezcGraphRenderer $renderer Renderer used to draw the chart
-     * @param ezcGraphBoundings $boundings Boundings of the axis
-     * @param ezcGraphCoordinate $start Axis starting point
-     * @param ezcGraphCoordinate $end Axis ending point
-     * @param ezcGraphChartElementAxis $axis Axis instance
-     * @return void
+     * Returns the text angle in degrees.
+     * 
+     * @param ezcGraphChartElementAxis $axis
+     * @param array $steps
+     * @return float
      */
-    public function renderLabels(
-        ezcGraphRenderer $renderer,
-        ezcGraphBoundings $boundings,
-        ezcGraphCoordinate $start,
-        ezcGraphCoordinate $end,
-        ezcGraphChartElementAxis $axis,
-        ezcGraphBoundings $innerBoundings = null )
-    {
-        // receive rendering parameters from axis
-        $steps = $axis->getSteps();
-        $this->steps = $steps;
-
-        $axisBoundings = new ezcGraphBoundings(
-            $start->x, $start->y,
-            $end->x, $end->y
-        );
-
-        // Determine normalized axis direction
-        $this->direction = new ezcGraphVector(
-            $end->x - $start->x,
-            $end->y - $start->y
-        );
-        $this->direction->unify();
-        $axisAngle = -$this->direction->angle( new ezcGraphVector( 1, 0 ) );
-
-        // Get axis space
-        $gridBoundings = null;
-        list( $xSpace, $ySpace ) = $this->getAxisSpace( $renderer, $boundings, $axis, $innerBoundings, $gridBoundings );
-
-        // Determine optimal angle if none specified
-        $this->determineAngle( $steps, $xSpace, $ySpace, $axisBoundings );
-
+    protected function determineTextOffset( ezcGraphChartElementAxis $axis, array $steps ) {
         // Determine additional required axis space by boxes
         $firstStep = reset( $steps );
         $lastStep = end( $steps );
 
+        $axisAngle = -$this->direction->angle( new ezcGraphVector( 1, 0 ) );
         $textAngle = $axisAngle + 
             deg2rad( $this->angle ) + 
             ( $axis->position & ( ezcGraph::TOP | ezcGraph::BOTTOM ) ? deg2rad( 270 ) : deg2rad( 90 ) );
@@ -221,6 +191,69 @@ class ezcGraphAxisRotatedLabelRenderer extends ezcGraphAxisLabelRenderer
             $this->offset = 0;
         }
 
+        return $degTextAngle;
+    }
+
+    /**
+     * Calculate label size
+     *
+     * Calculate the size of a single lable in a single step.
+     * 
+     * @param array $steps
+     * @param int $nr 
+     * @param array $step 
+     * @param float $xSpace 
+     * @param float $ySpace 
+     * @param ezcGraphBoundings $axisBoundings 
+     * @return float
+     */
+    protected function calculateLabelSize( array $steps, $nr, $step, $xSpace, $ySpace, ezcGraphBoundings $axisBoundings )
+    {
+        switch ( true )
+        {
+            case ( $nr === 0 ):
+                $labelSize = min(
+                    abs( 
+                        $xSpace * 2 * $this->direction->y +
+                        $ySpace * 2 * $this->direction->x ),
+                    abs( 
+                        $step->width * $axisBoundings->width * $this->direction->x +
+                        $step->width * $axisBoundings->height * $this->direction->y )
+                );
+                break;
+            case ( $step->isLast ):
+                $labelSize = min(
+                    abs( 
+                        $xSpace * 2 * $this->direction->y +
+                        $ySpace * 2 * $this->direction->x ),
+                    abs( 
+                        $steps[$nr - 1]->width * $axisBoundings->width * $this->direction->x +
+                        $steps[$nr - 1]->width * $axisBoundings->height * $this->direction->y )
+                );
+                break;
+            default:
+                $labelSize = abs( 
+                    $step->width * $axisBoundings->width * $this->direction->x +
+                    $step->width * $axisBoundings->height * $this->direction->y
+                );
+                break;
+        }
+
+        return $labelSize * cos( deg2rad( $this->angle ) );
+    }
+
+    /**
+     * Calculate general label length
+     * 
+     * @param ezcGraphCoordinate $start 
+     * @param ezcGraphCoordinate $end 
+     * @param float $xSpace 
+     * @param float $ySpace 
+     * @param ezcGraphBoundings $axisBoundings 
+     * @return float
+     */
+    protected function calculateLabelLength( ezcGraphCoordinate $start, ezcGraphCoordinate $end, $xSpace, $ySpace, ezcGraphBoundings $axisBoundings )
+    {
         $axisSpaceFactor = abs(
             ( $this->direction->x == 0 ? 0 :
                 $this->direction->x * $ySpace / $axisBoundings->width ) +
@@ -228,14 +261,14 @@ class ezcGraphAxisRotatedLabelRenderer extends ezcGraphAxisLabelRenderer
                 $this->direction->y * $xSpace / $axisBoundings->height )
         );
 
-        $start = new ezcGraphCoordinate(
-            $start->x + max( 0., $axisSpaceFactor * $this->offset ) * ( $end->x - $start->x ),
-            $start->y + max( 0., $axisSpaceFactor * $this->offset ) * ( $end->y - $start->y )
-        );
-        $end = new ezcGraphCoordinate(
-            $end->x + min( 0., $axisSpaceFactor * $this->offset ) * ( $end->x - $start->x ),
-            $end->y + min( 0., $axisSpaceFactor * $this->offset ) * ( $end->y - $start->y )
-        );
+        $axisWidth  = $end->x - $start->x;
+        $axisHeight = $end->y - $start->y;
+
+        $start->x += max( 0., $axisSpaceFactor * $this->offset ) * $axisWidth;
+        $start->y += max( 0., $axisSpaceFactor * $this->offset ) * $axisHeight;
+
+        $end->x += min( 0., $axisSpaceFactor * $this->offset ) * $axisWidth;
+        $end->y += min( 0., $axisSpaceFactor * $this->offset ) * $axisHeight;
 
         $labelLength = sqrt(
             pow(
@@ -249,6 +282,173 @@ class ezcGraphAxisRotatedLabelRenderer extends ezcGraphAxisLabelRenderer
         );
 
         $this->offset *= $axisSpaceFactor;
+        return $labelLength;
+    }
+
+    /**
+     * Render label text.
+     *
+     * Render the text of a single label, depending on the position, length and
+     * rotation of the label.
+     * 
+     * @param ezcGraphRenderer $renderer
+     * @param ezcGraphChartElementAxis $axis 
+     * @param ezcGraphCoordinate $position 
+     * @param string $label 
+     * @param float $degTextAngle 
+     * @param float $labelLength 
+     * @param float $labelSize 
+     * @param float $lengthReducement 
+     * @return void
+     */
+    protected function renderLabelText( ezcGraphRenderer $renderer, ezcGraphChartElementAxis $axis, ezcGraphCoordinate $position, $label, $degTextAngle, $labelLength, $labelSize, $lengthReducement )
+    {
+        switch ( true )
+        {
+            case ( ( ( $degTextAngle >= 0 ) && 
+                     ( $degTextAngle < 90 ) &&
+                     ( ( $axis->position === ezcGraph::LEFT ) ||
+                       ( $axis->position === ezcGraph::RIGHT )
+                     )
+                   ) ||
+                   ( ( $degTextAngle >= 270 ) && 
+                     ( $degTextAngle < 360 ) &&
+                     ( ( $axis->position === ezcGraph::TOP ) ||
+                       ( $axis->position === ezcGraph::BOTTOM )
+                     )
+                   )
+                 ):
+                $labelBoundings = new ezcGraphBoundings(
+                    $position->x,
+                    $position->y,
+                    $position->x + abs( $labelLength ) - $lengthReducement,
+                    $position->y + $labelSize
+                );
+                $labelAlignement = ezcGraph::LEFT | ezcGraph::TOP;
+                $labelRotation = $degTextAngle;
+                break;
+            case ( ( ( $degTextAngle >= 90 ) && 
+                     ( $degTextAngle < 180 ) &&
+                     ( ( $axis->position === ezcGraph::LEFT ) ||
+                       ( $axis->position === ezcGraph::RIGHT )
+                     )
+                   ) ||
+                   ( ( $degTextAngle >= 180 ) && 
+                     ( $degTextAngle < 270 ) &&
+                     ( ( $axis->position === ezcGraph::TOP ) ||
+                       ( $axis->position === ezcGraph::BOTTOM )
+                     )
+                   )
+                 ):
+                $labelBoundings = new ezcGraphBoundings(
+                    $position->x - abs( $labelLength ) + $lengthReducement,
+                    $position->y,
+                    $position->x,
+                    $position->y + $labelSize
+                );
+                $labelAlignement = ezcGraph::RIGHT | ezcGraph::TOP;
+                $labelRotation = $degTextAngle - 180;
+                break;
+            case ( ( ( $degTextAngle >= 180 ) && 
+                     ( $degTextAngle < 270 ) &&
+                     ( ( $axis->position === ezcGraph::LEFT ) ||
+                       ( $axis->position === ezcGraph::RIGHT )
+                     )
+                   ) ||
+                   ( ( $degTextAngle >= 90 ) && 
+                     ( $degTextAngle < 180 ) &&
+                     ( ( $axis->position === ezcGraph::TOP ) ||
+                       ( $axis->position === ezcGraph::BOTTOM )
+                     )
+                   )
+                 ):
+                $labelBoundings = new ezcGraphBoundings(
+                    $position->x - abs( $labelLength ) + $lengthReducement,
+                    $position->y - $labelSize,
+                    $position->x,
+                    $position->y
+                );
+                $labelAlignement = ezcGraph::RIGHT | ezcGraph::BOTTOM;
+                $labelRotation = $degTextAngle - 180;
+                break;
+            case ( ( ( $degTextAngle >= 270 ) && 
+                     ( $degTextAngle < 360 ) &&
+                     ( ( $axis->position === ezcGraph::LEFT ) ||
+                       ( $axis->position === ezcGraph::RIGHT )
+                     )
+                   ) ||
+                   ( ( $degTextAngle >= 0 ) && 
+                     ( $degTextAngle < 90 ) &&
+                     ( ( $axis->position === ezcGraph::TOP ) ||
+                       ( $axis->position === ezcGraph::BOTTOM )
+                     )
+                   )
+                 ):
+                $labelBoundings = new ezcGraphBoundings(
+                    $position->x,
+                    $position->y,
+                    $position->x - abs( $labelLength ) + $lengthReducement,
+                    $position->y + $labelSize
+                );
+                $labelAlignement = ezcGraph::LEFT | ezcGraph::TOP;
+                $labelRotation = $degTextAngle;
+                break;
+        }
+
+        $renderer->drawText(
+            $labelBoundings,
+            $label,
+            $labelAlignement,
+            new ezcGraphRotation(
+                $labelRotation,
+                $position
+            )
+        );
+    }
+
+    /**
+     * Render Axis labels
+     *
+     * Render labels for an axis.
+     *
+     * @param ezcGraphRenderer $renderer Renderer used to draw the chart
+     * @param ezcGraphBoundings $boundings Boundings of the axis
+     * @param ezcGraphCoordinate $start Axis starting point
+     * @param ezcGraphCoordinate $end Axis ending point
+     * @param ezcGraphChartElementAxis $axis Axis instance
+     * @return void
+     */
+    public function renderLabels(
+        ezcGraphRenderer $renderer,
+        ezcGraphBoundings $boundings,
+        ezcGraphCoordinate $start,
+        ezcGraphCoordinate $end,
+        ezcGraphChartElementAxis $axis,
+        ezcGraphBoundings $innerBoundings = null )
+    {
+        // receive rendering parameters from axis
+        $steps = $axis->getSteps();
+
+        $axisBoundings = new ezcGraphBoundings(
+            $start->x, $start->y,
+            $end->x, $end->y
+        );
+
+        // Determine normalized axis direction
+        $this->direction = new ezcGraphVector(
+            $end->x - $start->x,
+            $end->y - $start->y
+        );
+        $this->direction->unify();
+
+        // Get axis space
+        $gridBoundings = null;
+        list( $xSpace, $ySpace ) = $this->getAxisSpace( $renderer, $boundings, $axis, $innerBoundings, $gridBoundings );
+
+        // Determine optimal angle if none specified
+        $this->determineAngle( $steps, $xSpace, $ySpace, $axisBoundings );
+        $degTextAngle = $this->determineTextOffset( $axis, $steps );
+        $labelLength  = $this->calculateLabelLength( $start, $end, $xSpace, $ySpace, $axisBoundings );
 
         // Draw steps and grid
         foreach ( $steps as $nr => $step )
@@ -264,165 +464,22 @@ class ezcGraphAxisRotatedLabelRenderer extends ezcGraphAxisLabelRenderer
             );
 
             // Calculate label boundings
-            switch ( true )
-            {
-                case ( $nr === 0 ):
-                    $labelSize = min(
-                        abs( 
-                            $xSpace * 2 * $this->direction->y +
-                            $ySpace * 2 * $this->direction->x ),
-                        abs( 
-                            $step->width * $axisBoundings->width * $this->direction->x +
-                            $step->width * $axisBoundings->height * $this->direction->y )
-                    );
-                    break;
-                case ( $step->isLast ):
-                    $labelSize = min(
-                        abs( 
-                            $xSpace * 2 * $this->direction->y +
-                            $ySpace * 2 * $this->direction->x ),
-                        abs( 
-                            $steps[$nr - 1]->width * $axisBoundings->width * $this->direction->x +
-                            $steps[$nr - 1]->width * $axisBoundings->height * $this->direction->y )
-                    );
-                    break;
-                default:
-                    $labelSize = abs( 
-                        $step->width * $axisBoundings->width * $this->direction->x +
-                        $step->width * $axisBoundings->height * $this->direction->y
-                    );
-                    break;
-            }
-
-            $labelSize = $labelSize * cos( deg2rad( $this->angle ) );
+            $labelSize = $this->calculateLabelSize( $steps, $nr, $step, $xSpace, $ySpace, $axisBoundings );
             $lengthReducement = min(
                 abs( tan( deg2rad( $this->angle ) ) * ( $labelSize / 2 ) ),
                 abs( $labelLength / 2 )
             );
 
-            switch ( true )
-            {
-                case ( ( ( $degTextAngle >= 0 ) && 
-                         ( $degTextAngle < 90 ) &&
-                         ( ( $axis->position === ezcGraph::LEFT ) ||
-                           ( $axis->position === ezcGraph::RIGHT )
-                         )
-                       ) ||
-                       ( ( $degTextAngle >= 270 ) && 
-                         ( $degTextAngle < 360 ) &&
-                         ( ( $axis->position === ezcGraph::TOP ) ||
-                           ( $axis->position === ezcGraph::BOTTOM )
-                         )
-                       )
-                     ):
-                    $labelBoundings = new ezcGraphBoundings(
-                        $position->x,
-                        $position->y,
-                        $position->x + abs( $labelLength ) - $lengthReducement,
-                        $position->y + $labelSize
-                    );
-                    $labelAlignement = ezcGraph::LEFT | ezcGraph::TOP;
-                    $labelRotation = $degTextAngle;
-                    break;
-                case ( ( ( $degTextAngle >= 90 ) && 
-                         ( $degTextAngle < 180 ) &&
-                         ( ( $axis->position === ezcGraph::LEFT ) ||
-                           ( $axis->position === ezcGraph::RIGHT )
-                         )
-                       ) ||
-                       ( ( $degTextAngle >= 180 ) && 
-                         ( $degTextAngle < 270 ) &&
-                         ( ( $axis->position === ezcGraph::TOP ) ||
-                           ( $axis->position === ezcGraph::BOTTOM )
-                         )
-                       )
-                     ):
-                    $labelBoundings = new ezcGraphBoundings(
-                        $position->x - abs( $labelLength ) + $lengthReducement,
-                        $position->y,
-                        $position->x,
-                        $position->y + $labelSize
-                    );
-                    $labelAlignement = ezcGraph::RIGHT | ezcGraph::TOP;
-                    $labelRotation = $degTextAngle - 180;
-                    break;
-                case ( ( ( $degTextAngle >= 180 ) && 
-                         ( $degTextAngle < 270 ) &&
-                         ( ( $axis->position === ezcGraph::LEFT ) ||
-                           ( $axis->position === ezcGraph::RIGHT )
-                         )
-                       ) ||
-                       ( ( $degTextAngle >= 90 ) && 
-                         ( $degTextAngle < 180 ) &&
-                         ( ( $axis->position === ezcGraph::TOP ) ||
-                           ( $axis->position === ezcGraph::BOTTOM )
-                         )
-                       )
-                     ):
-                    $labelBoundings = new ezcGraphBoundings(
-                        $position->x - abs( $labelLength ) + $lengthReducement,
-                        $position->y - $labelSize,
-                        $position->x,
-                        $position->y
-                    );
-                    $labelAlignement = ezcGraph::RIGHT | ezcGraph::BOTTOM;
-                    $labelRotation = $degTextAngle - 180;
-                    break;
-                case ( ( ( $degTextAngle >= 270 ) && 
-                         ( $degTextAngle < 360 ) &&
-                         ( ( $axis->position === ezcGraph::LEFT ) ||
-                           ( $axis->position === ezcGraph::RIGHT )
-                         )
-                       ) ||
-                       ( ( $degTextAngle >= 0 ) && 
-                         ( $degTextAngle < 90 ) &&
-                         ( ( $axis->position === ezcGraph::TOP ) ||
-                           ( $axis->position === ezcGraph::BOTTOM )
-                         )
-                       )
-                     ):
-                    $labelBoundings = new ezcGraphBoundings(
-                        $position->x,
-                        $position->y,
-                        $position->x - abs( $labelLength ) + $lengthReducement,
-                        $position->y + $labelSize
-                    );
-                    $labelAlignement = ezcGraph::LEFT | ezcGraph::TOP;
-                    $labelRotation = $degTextAngle;
-                    break;
-            }
-
-            $renderer->drawText(
-                $labelBoundings,
-                $step->label,
-                $labelAlignement,
-                new ezcGraphRotation(
-                    $labelRotation,
-                    $position
-                )
-            );
+            $this->renderLabelText( $renderer, $axis, $position, $step->label, $degTextAngle, $labelLength, $labelSize, $lengthReducement );
 
-            // major grid
+            // Major grid
             if ( $axis->majorGrid )
             {
-                $this->drawGrid( 
-                    $renderer, 
-                    $gridBoundings, 
-                    $position,
-                    $stepSize,
-                    $axis->majorGrid
-                );
+                $this->drawGrid( $renderer, $gridBoundings, $position, $stepSize, $axis->majorGrid );
             }
             
-            // major step
-            $this->drawStep( 
-                $renderer, 
-                $position,
-                $this->direction, 
-                $axis->position, 
-                $this->majorStepSize, 
-                $axis->border
-            );
+            // Major step
+            $this->drawStep( $renderer, $position, $this->direction, $axis->position, $this->majorStepSize, $axis->border );
         }
     }