Add new widget "spacer" which adds an empty space between widgets

The attribute "size" allows to define the spacing in px.

The special value "expand" can be used to make the spacer consume
all available space in the parent.

6 files changed, 138 insertions, 1 deletions

diff --git a/src/extension/CMakeLists.txt b/src/extension/CMakeLists.txt
index a82ff3fbe..032b9cd4c 100644
--- a/src/extension/CMakeLists.txt
+++ b/src/extension/CMakeLists.txt
@@ -65,6 +65,7 @@ set(extension_SRC
 	prefdialog/widget-box.cpp
 	prefdialog/widget-label.cpp
 	prefdialog/widget-separator.cpp
+	prefdialog/widget-spacer.cpp
 
 	# ------
 	# Header
@@ -142,6 +143,7 @@ set(extension_SRC
 	prefdialog/widget-box.h
 	prefdialog/widget-label.h
 	prefdialog/widget-separator.h
+	prefdialog/widget-spacer.h
 )
 
 if(WIN32)
diff --git a/src/extension/prefdialog/widget-box.cpp b/src/extension/prefdialog/widget-box.cpp
index d7b93e3ff..2c9d24f4a 100644
--- a/src/extension/prefdialog/widget-box.cpp
+++ b/src/extension/prefdialog/widget-box.cpp
@@ -84,6 +84,12 @@ Gtk::Widget *WidgetBox::get_widget(sigc::signal<void> *changeSignal)
                                               // revisit this later, possibly implementing GtkFrame or similar
     box->set_spacing(GUI_BOX_SPACING);
 
+    if (_orientation == HORIZONTAL) {
+        box->set_vexpand(false);
+    } else {
+        box->set_hexpand(false);
+    }
+
     // add child widgets onto page (if any)
     for (auto child : _children) {
         Gtk::Widget *child_widget = child->get_widget(changeSignal);
diff --git a/src/extension/prefdialog/widget-separator.cpp b/src/extension/prefdialog/widget-separator.cpp
index 94778e027..d78894b62 100644
--- a/src/extension/prefdialog/widget-separator.cpp
+++ b/src/extension/prefdialog/widget-separator.cpp
@@ -35,6 +35,7 @@ Gtk::Widget *WidgetSeparator::get_widget(sigc::signal<void> *changeSignal)
 
     Gtk::Separator *separator = Gtk::manage(new Gtk::Separator());
     separator->show();
+
     return dynamic_cast<Gtk::Widget *>(separator);
 }
 
diff --git a/src/extension/prefdialog/widget-spacer.cpp b/src/extension/prefdialog/widget-spacer.cpp
new file mode 100644
index 000000000..350aeb4f2
--- /dev/null
+++ b/src/extension/prefdialog/widget-spacer.cpp
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Spacer widget for extensions
+ *//*
+ * Authors:
+ *   Patrick Storz <eduard.braun2@gmx.de>
+ *
+ * Copyright (C) 2019 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "widget-spacer.h"
+
+#include <gtkmm/box.h>
+
+#include "xml/node.h"
+#include "extension/extension.h"
+
+namespace Inkscape {
+namespace Extension {
+
+
+WidgetSpacer::WidgetSpacer(Inkscape::XML::Node *xml, Inkscape::Extension::Extension *ext)
+    : InxWidget(xml, ext)
+{
+    // get size
+    const char *size = xml->attribute("size");
+    if (size) {
+        _size = strtol(size, nullptr, 0);
+        if (_size == 0) {
+            if (!strcmp(size, "expand")) {
+                _expand = true;
+            } else {
+                g_warning("Invalid value ('%s') for size spacer in extension '%s'", size, _extension->get_id());
+            }
+        }
+    }
+}
+
+/** \brief  Create a label for the description */
+Gtk::Widget *WidgetSpacer::get_widget(sigc::signal<void> *changeSignal)
+{
+    if (_hidden) {
+        return nullptr;
+    }
+
+    Gtk::Box *spacer = Gtk::manage(new Gtk::Box());
+    spacer->set_border_width(_size/2);
+
+    if (_expand) {
+        spacer->set_hexpand();
+        spacer->set_vexpand();
+    } else {
+        spacer->set_margin_start(_size);
+        spacer->set_margin_top(_size);
+    }
+
+    spacer->show();
+
+    return dynamic_cast<Gtk::Widget *>(spacer);
+}
+
+}  /* namespace Extension */
+}  /* namespace Inkscape */
diff --git a/src/extension/prefdialog/widget-spacer.h b/src/extension/prefdialog/widget-spacer.h
new file mode 100644
index 000000000..467b5f95b
--- /dev/null
+++ b/src/extension/prefdialog/widget-spacer.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Spacer widget for extensions
+ *//*
+ * Authors:
+ *   Patrick Storz <eduard.braun2@gmx.de>
+ *
+ * Copyright (C) 2019 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INK_EXTENSION_WIDGET_SPACER_H
+#define SEEN_INK_EXTENSION_WIDGET_SPACER_H
+
+#include "widget.h"
+
+#include <glibmm/ustring.h>
+
+namespace Gtk {
+	class Widget;
+}
+
+namespace Inkscape {
+namespace Xml {
+	class Node;
+}
+
+namespace Extension {
+
+/** \brief  A separator widget */
+class WidgetSpacer : public InxWidget {
+public:
+    WidgetSpacer(Inkscape::XML::Node *xml, Inkscape::Extension::Extension *ext);
+
+    Gtk::Widget *get_widget(sigc::signal<void> *changeSignal) override;
+
+private:
+    /** size of the spacer in px */
+    int _size = GUI_BOX_MARGIN;
+
+    /** should the spacer be flexible and expand? */
+    bool _expand = false;
+};
+
+}  /* namespace Extension */
+}  /* namespace Inkscape */
+
+#endif /* SEEN_INK_EXTENSION_WIDGET_SPACER_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/extension/prefdialog/widget.cpp b/src/extension/prefdialog/widget.cpp
index eb9d23e07..da4b6545d 100644
--- a/src/extension/prefdialog/widget.cpp
+++ b/src/extension/prefdialog/widget.cpp
@@ -15,6 +15,7 @@
 #include "widget-box.h"
 #include "widget-label.h"
 #include "widget-separator.h"
+#include "widget-spacer.h"
 
 #include <algorithm>
 
@@ -51,6 +52,8 @@ InxWidget *InxWidget::make(Inkscape::XML::Node *in_repr, Inkscape::Extension::Ex
         widget = new WidgetLabel(in_repr, in_ext);
     } else if (!strcmp(name, "separator")) {
         widget = new WidgetSeparator(in_repr, in_ext);
+    } else if (!strcmp(name, "spacer")) {
+        widget = new WidgetSpacer(in_repr, in_ext);
     } else if (!strcmp(name, "param")) {
         widget = InxParameter::make(in_repr, in_ext);
     } else {
@@ -64,7 +67,7 @@ InxWidget *InxWidget::make(Inkscape::XML::Node *in_repr, Inkscape::Extension::Ex
 bool InxWidget::is_valid_widget_name(const char *name)
 {
     // keep in sync with names supported in InxWidget::make() above
-    static const std::vector<std::string> valid_names = {"hbox", "vbox", "label", "separator", "param"};
+    static const std::vector<std::string> valid_names = {"hbox", "vbox", "label", "separator", "spacer", "param"};
 
     if (std::find(valid_names.begin(), valid_names.end(), name) != valid_names.end()) {
         return true;