Allow adding featurepoints

[Findus23]

Hi, many thanks for your great library.

I am currently trying to replace the old, original sparkline library with your version in Piwik (matomo-org/matomo#12066)
Unfortunately there is one feature we used in the old library that is missing in your library and would be nice to have:
The ability to set featurepoints.
https://github.com/piwik/piwik/blob/9243b9a7b6fae8237596f76cda1fe8b6816463af/core/Visualization/Sparkline.php#L138-L140

Those are simply single colored dots that can be added e.g. to indicate the minimum or maximum.

Maybe you could imprement a simple interface that allows adding points by x and y value, color and diameter?

Thanks again for providing a modern library.

[onenaka]

Thank you respons😘

[Findus23]

Another idea:
As it is hard to know the right coodinates, I'd propose a setting to add Minimum and Maximum dots.

diff --git a/src/Sparkline.php b/src/Sparkline.php
index c189783..0aaba20 100644
--- a/src/Sparkline.php
+++ b/src/Sparkline.php
@@ -44,6 +44,16 @@ class Sparkline
      */
     protected $fillColor = array(230, 242, 250);
 
+    /**
+     * @var array (rgb)
+     */
+    protected $minimumColor;
+
+    /**
+     * @var array (rgb)
+     */
+    protected $maximumColor;
+
     /**
      * @var float (px)
      * Default: 1.75px
@@ -254,6 +264,41 @@ class Sparkline
         $this->fillColor = array($red, $green, $blue);
     }
 
+    /**
+     * @param string $color (hexadecimal)
+     */
+    public function setMinimumColorHex($color) {
+        list($red, $green, $blue) = $this->colorHexToRGB($color);
+        $this->setMinimumColorRGB($red, $green, $blue);
+    }
+
+    /**
+     * @param int $red
+     * @param int $green
+     * @param int $blue
+     */
+    public function setMinimumColorRGB($red, $green, $blue) {
+        $this->minimumColor = array($red, $green, $blue);
+    }
+
+    /**
+     * @param string $color (hexadecimal)
+     */
+    public function setMaximumColorHex($color) {
+        list($red, $green, $blue) = $this->colorHexToRGB($color);
+        $this->setMaximumColorRGB($red, $green, $blue);
+    }
+
+    /**
+     * @param int $red
+     * @param int $green
+     * @param int $blue
+     */
+    public function setMaximumColorRGB($red, $green, $blue) {
+        $this->maximumColor = array($red, $green, $blue);
+    }
+
+
     /**
      * @param array $data
      */
@@ -291,6 +336,11 @@ class Sparkline
         $count = count($this->data);
         $step = $width / ($count - 1);
         $max = max($this->data);
+        $maxs = array_keys($this->data, $max);
+        $maxIndex = end($maxs);
+        $min = min($this->data);
+        $mins = array_keys($this->data, $min);
+        $minIndex = end($mins);
         if ($this->base) {
             $max = $this->base;
         }
@@ -357,6 +407,14 @@ class Sparkline
             list($pictureX1, $pictureY1, $pictureX2, $pictureY2) = $coordinates;
             imageline($picture, $pictureX1, $pictureY1, $pictureX2, $pictureY2, $lineColor);
         }
+        if (isset($this->minimumColor)) {
+            $minimumColor = imagecolorallocate($picture, $this->minimumColor[0], $this->minimumColor[1], $this->minimumColor[2]);
+            imagefilledellipse($picture, $minIndex * $step, $height - $this->data[$minIndex], 5 * $this->ratioComputing, 5 * $this->ratioComputing, $minimumColor);
+        }
+        if (isset($this->maximumColor)) {
+            $maximumColor = imagecolorallocate($picture, $this->maximumColor[0], $this->maximumColor[1], $this->maximumColor[2]);
+            imagefilledellipse($picture, $maxIndex * $step, $height - $this->data[$maxIndex], 5 * $this->ratioComputing, 5 * $this->ratioComputing, $maximumColor);
+        }
         $sparkline = imagecreatetruecolor($this->width, $this->height);
         imagealphablending($sparkline, false);
         imagecopyresampled($sparkline, $picture, 0, 0, 0, 0, $this->width, $this->height, $width, $height);

[davaxi]

Pull request merged. Thans @Findus23 👍

[davaxi]

With refactoring i work this week to add method to add dots on chart by index

[davaxi]

Method 'addPoint' add on release 1.1.0