Added SCROLL_TOP and SCROLL_BOTTOM (MontFerret#174)

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()
+}