1 files changed, 133 insertions, 0 deletions
diff --git a/library/Icingadb/Widget/StateChange.php b/library/Icingadb/Widget/StateChange.php
new file mode 100644
index 0000000..a9987be
--- /dev/null
+++ b/library/Icingadb/Widget/StateChange.php
@@ -0,0 +1,133 @@
+<?php
+
+/* Icinga DB Web | (c) 2020 Icinga GmbH | GPLv2 */
+
+namespace Icinga\Module\Icingadb\Widget;
+
+use ipl\Html\BaseHtmlElement;
+use ipl\Web\Widget\Icon;
+use ipl\Web\Widget\StateBall;
+
+class StateChange extends BaseHtmlElement
+{
+    protected $previousState;
+
+    protected $state;
+
+    protected $previousStateBallSize = StateBall::SIZE_BIG;
+
+    protected $currentStateBallSize = StateBall::SIZE_BIG;
+
+    protected $defaultAttributes = ['class' => 'state-change'];
+
+    protected $tag = 'div';
+
+    /** @var ?Icon Current state ball icon */
+    protected $icon;
+
+    /** @var bool Whether the state is handled */
+    protected $isHandled = false;
+
+    public function __construct(string $state, string $previousState)
+    {
+        $this->previousState = $previousState;
+        $this->state = $state;
+    }
+
+    /**
+     * Set the state ball size for the previous state
+     *
+     * @param string $size
+     *
+     * @return $this
+     */
+    public function setPreviousStateBallSize(string $size): self
+    {
+        $this->previousStateBallSize = $size;
+
+        return $this;
+    }
+
+    /**
+     * Set the state ball size for the current state
+     *
+     * @param string $size
+     *
+     * @return $this
+     */
+    public function setCurrentStateBallSize(string $size): self
+    {
+        $this->currentStateBallSize = $size;
+
+        return $this;
+    }
+
+    /**
+     * Set the current state ball icon
+     *
+     * @param $icon
+     *
+     * @return $this
+     */
+    public function setIcon($icon): self
+    {
+        $this->icon = $icon;
+
+        return $this;
+    }
+
+    /**
+     * Set whether the current state is handled
+     *
+     * @return $this
+     */
+    public function setHandled($isHandled = true): self
+    {
+        $this->isHandled = $isHandled;
+
+        return $this;
+    }
+
+    protected function assemble()
+    {
+        $currentStateBall = (new StateBall($this->state, $this->currentStateBallSize))
+            ->add($this->icon);
+
+        if ($this->isHandled) {
+            $currentStateBall->getAttributes()->add('class', 'handled');
+        }
+
+        $previousStateBall = new StateBall($this->previousState, $this->previousStateBallSize);
+        if ($this->isRightBiggerThanLeft()) {
+            $this->getAttributes()->add('class', 'reversed-state-balls');
+
+            $this->addHtml($currentStateBall, $previousStateBall);
+        } else {
+            $this->addHtml($previousStateBall, $currentStateBall);
+        }
+    }
+
+    protected function isRightBiggerThanLeft(): bool
+    {
+        $left = $this->previousStateBallSize;
+        $right = $this->currentStateBallSize;
+
+        if ($left === $right) {
+            return false;
+        } elseif ($left === StateBall::SIZE_LARGE) {
+            return false;
+        }
+
+        $map = [
+            StateBall::SIZE_BIG => [false, [StateBall::SIZE_LARGE]],
+            StateBall::SIZE_MEDIUM_LARGE => [false, [StateBall::SIZE_BIG, StateBall::SIZE_LARGE]],
+            StateBall::SIZE_MEDIUM => [true, [StateBall::SIZE_TINY, StateBall::SIZE_SMALL]],
+            StateBall::SIZE_SMALL => [true, [StateBall::SIZE_TINY]]
+        ];
+
+        list($negate, $sizes) = $map[$left];
+        $found = in_array($right, $sizes, true);
+
+        return ($negate && ! $found) || (! $negate && $found);
+    }
+}