implement progressbar

src/app/browser/main/tab/page/progressbar.cpp

@@ -0,0 +1,53 @@
+#include "progressbar.hpp"
+
+using namespace app::browser::main::tab::page;
+
+Progressbar::Progressbar()
+{
+    set_margin_top(
+        MARGIN
+    );
+
+    set_margin_bottom(
+        MARGIN
+    );
+
+    set_pulse_step(
+        PULSE_STEP
+    );
+
+    set_opacity(0);
+}
+
+Progressbar::~Progressbar() = default;
+
+// Public actions
+void Progressbar::set(
+    double fraction
+) {
+    // Toggle transparency
+    set_opacity(
+        fraction < 1 ? 1 : 0
+    );
+
+    // Reset initial progress
+    progress = fraction;
+
+    // Animate progress function
+    Glib::signal_timeout().connect(
+        [this]() -> bool
+        {
+            double current = get_fraction();
+
+            if (current < progress)
+            {
+                set_fraction(
+                    current + PULSE_STEP
+                );
+            }
+
+            return current < 1;
+        },
+        ANIMATION_TIME
+    );
+}