From c89014b915fb28acc20f8bcb97bef1ce9a2030ac Mon Sep 17 00:00:00 2001
From: Tim Voronov <ziflex@users.noreply.github.com>
Date: Mon, 12 Nov 2018 22:26:02 -0500
Subject: [PATCH] Added SCROLL_TOP and SCROLL_BOTTOM (#174)

---
 pkg/stdlib/html/scroll.go | 56 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 pkg/stdlib/html/scroll.go

diff --git a/pkg/stdlib/html/scroll.go b/pkg/stdlib/html/scroll.go
new file mode 100644
index 000000000..41d4d2be9
--- /dev/null
+++ b/pkg/stdlib/html/scroll.go
@@ -0,0 +1,56 @@
+package html
+
+import (
+	"context"
+	"github.com/MontFerret/ferret/pkg/html/dynamic"
+	"github.com/MontFerret/ferret/pkg/runtime/core"
+	"github.com/MontFerret/ferret/pkg/runtime/values"
+)
+
+// ScrollTop Scrolls the document's window to its top.
+// @param doc (Document) - Target document.
+func ScrollTop(_ context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 1, 1)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	err = core.ValidateType(args[0], core.HTMLDocumentType)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	doc, ok := args[0].(*dynamic.HTMLDocument)
+
+	if !ok {
+		return values.None, core.Errors(core.ErrInvalidType, ErrNotDynamic)
+	}
+
+	return values.None, doc.ScrollTop()
+}
+
+// ScrollTop Scrolls the document's window to its bottom.
+// @param doc (Document) - Target document.
+func ScrollBottom(_ context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 1, 1)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	err = core.ValidateType(args[0], core.HTMLDocumentType)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	doc, ok := args[0].(*dynamic.HTMLDocument)
+
+	if !ok {
+		return values.None, core.Errors(core.ErrInvalidType, ErrNotDynamic)
+	}
+
+	return values.None, doc.ScrollBottom()
+}