Initialize all variables

15 files changed, 217 insertions, 151 deletions

diff --git a/.clang-tidy b/.clang-tidy
index a07aa88..36cfbc7 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -32,7 +32,6 @@ Checks: >
   -clang-analyzer-cplusplus.NewDeleteLeaks,
   -clang-analyzer-unix.Malloc,
   -cppcoreguidelines-avoid-non-const-global-variables,
-  -cppcoreguidelines-init-variables,
   -cppcoreguidelines-macro-usage,
   -cppcoreguidelines-non-private-member-variables-in-classes,
   -cppcoreguidelines-owning-memory,
@@ -69,7 +68,6 @@ Checks: >
   -readability-container-size-empty,
   -readability-implicit-bool-conversion,
   -readability-inconsistent-declaration-parameter-name,
-  -readability-isolate-declaration,
   -readability-make-member-function-const,
 WarningsAsErrors: '*'
 HeaderFilterRegex: '.*'
diff --git a/ganv/Edge.hpp b/ganv/Edge.hpp
index c7056a3..3dd08f3 100644
--- a/ganv/Edge.hpp
+++ b/ganv/Edge.hpp
@@ -59,6 +59,9 @@ public:
 		: Item(GANV_ITEM(gobj))
 	{}
 
+	Edge(const Edge& copy) = delete;
+	Edge& operator=(const Edge& other) = delete;
+
 	~Edge() override {
 		if (_gobj && ganv_item_get_parent(_gobj)) {
 			g_object_unref(_gobj);
@@ -81,10 +84,6 @@ public:
 
 	GanvEdge*       gobj()       { return reinterpret_cast<GanvEdge*>(_gobj); }
 	const GanvEdge* gobj() const { return reinterpret_cast<GanvEdge*>(_gobj); }
-
-private:
-	Edge(const Edge& copy);
-	Edge& operator=(const Edge& other);
 };
 
 } // namespace Ganv
diff --git a/ganv/Item.hpp b/ganv/Item.hpp
index 09e2f13..1dfe4eb 100644
--- a/ganv/Item.hpp
+++ b/ganv/Item.hpp
@@ -21,7 +21,6 @@
 #include "ganv/wrap.hpp"
 
 #include <gdk/gdk.h>
-#include <gdkmm/event.h>
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gclosure.h>
diff --git a/ganv/Node.hpp b/ganv/Node.hpp
index 95c66a4..e075e73 100644
--- a/ganv/Node.hpp
+++ b/ganv/Node.hpp
@@ -103,7 +103,7 @@ private:
 	static void on_notify_bool(GObject*    gobj,
 	                           GParamSpec* pspec,
 	                           gpointer    signal) {
-		gboolean value;
+		gboolean value = FALSE;
 		g_object_get(gobj, g_param_spec_get_name(pspec), &value, nullptr);
 		static_cast<sigc::signal<bool, gboolean>*>(signal)->emit(value);
 	}
diff --git a/src/Canvas.cpp b/src/Canvas.cpp
index f3b2499..fdd7358 100644
--- a/src/Canvas.cpp
+++ b/src/Canvas.cpp
@@ -48,7 +48,6 @@
 #include <cairo.h>
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms-compat.h>
-#include <gdkmm/event.h>
 #include <gdkmm/gc.h>
 #include <gdkmm/screen.h>
 #include <gdkmm/window.h>
@@ -78,6 +77,7 @@
 #include <iostream>
 #include <map>
 #include <set>
+#include <sstream>
 #include <string>
 #include <utility>
 #include <vector>
@@ -541,8 +541,8 @@ GanvCanvasImpl::first_edge_to(const GanvNode* head)
 static void
 select_if_tail_is_selected(GanvEdge* edge, void*)
 {
-	GanvNode* tail = edge->impl->tail;
-	gboolean  selected;
+	GanvNode* tail     = edge->impl->tail;
+	gboolean  selected = FALSE;
 	g_object_get(tail, "selected", &selected, NULL);
 	if (!selected && GANV_IS_PORT(tail)) {
 		g_object_get(ganv_port_get_module(GANV_PORT(tail)),
@@ -557,8 +557,8 @@ select_if_tail_is_selected(GanvEdge* edge, void*)
 static void
 select_if_head_is_selected(GanvEdge* edge, void*)
 {
-	GanvNode* head = edge->impl->head;
-	gboolean  selected;
+	GanvNode* head     = edge->impl->head;
+	gboolean  selected = FALSE;
 	g_object_get(head, "selected", &selected, NULL);
 	if (!selected && GANV_IS_PORT(head)) {
 		g_object_get(ganv_port_get_module(GANV_PORT(head)),
@@ -700,7 +700,7 @@ GanvCanvasImpl::layout_dot(const std::string& filename)
 			}
 
 			// Label row
-			std::stringstream colspan;
+			std::ostringstream colspan;
 			colspan << (flow_right ? 1 : (n_cols + 1));
 			html += std::string("<TR><TD BORDER=\"0\" CELLPADDING=\"2\" COLSPAN=\"")
 				+ colspan.str()
@@ -826,7 +826,10 @@ get_region(GanvNode* node)
 {
 	GanvItem* item = &node->item;
 
-	double x1, y1, x2, y2;
+	double x1 = 0.0;
+	double y1 = 0.0;
+	double x2 = 0.0;
+	double y2 = 0.0;
 	ganv_item_get_bounds(item, &x1, &y1, &x2, &y2);
 
 	Region reg;
@@ -1040,7 +1043,7 @@ GanvCanvasImpl::select_port(GanvPort* p, bool unique)
 void
 GanvCanvasImpl::select_port_toggle(GanvPort* port, int mod_state)
 {
-	gboolean selected;
+	gboolean selected = FALSE;
 	g_object_get(G_OBJECT(port), "selected", &selected, NULL);
 	if ((mod_state & GDK_CONTROL_MASK)) {
 		if (selected)
@@ -1151,7 +1154,9 @@ bool
 GanvCanvasImpl::on_event(GdkEvent* event)
 {
 	static const int scroll_increment = 10;
-	int scroll_x, scroll_y;
+
+	int scroll_x = 0;
+	int scroll_y = 0;
 
 	bool handled = false;
 	switch (event->type) {
@@ -1269,9 +1274,9 @@ static void
 get_motion_coords(GdkEventMotion* motion, double* x, double* y)
 {
 	if (motion->is_hint) {
-		gint px;
-		gint py;
-		GdkModifierType state;
+		gint            px    = 0;
+		gint            py    = 0;
+		GdkModifierType state = (GdkModifierType)0;
 		gdk_window_get_pointer(motion->window, &px, &py, &state);
 		*x = px;
 		*y = py;
@@ -1309,7 +1314,8 @@ GanvCanvasImpl::select_drag_handler(GdkEvent* event)
 		return true;
 	} else if (event->type == GDK_MOTION_NOTIFY && _drag_state == SELECT) {
 		assert(_select_rect);
-		double x, y;
+		double x = 0.0;
+		double y = 0.0;
 		get_motion_coords(&event->motion, &x, &y);
 		_select_rect->impl->coords.x1 = MIN(_select_start_x, x);
 		_select_rect->impl->coords.y1 = MIN(_select_start_y, y);
@@ -1331,7 +1337,7 @@ GanvCanvasImpl::select_drag_handler(GdkEvent* event)
 				    ganv_box_get_y1(_select_rect),
 				    ganv_box_get_x2(_select_rect),
 				    ganv_box_get_y2(_select_rect))) {
-				gboolean selected;
+				gboolean selected = FALSE;
 				g_object_get(G_OBJECT(node), "selected", &selected, NULL);
 				if (selected) {
 					ganv_canvas_unselect_node(_gcanvas, node);
@@ -1373,7 +1379,8 @@ GanvCanvasImpl::connect_drag_handler(GdkEvent* event)
 	}
 
 	if (event->type == GDK_MOTION_NOTIFY) {
-		double x, y;
+		double x = 0.0;
+		double y = 0.0;
 		get_motion_coords(&event->motion, &x, &y);
 
 		if (!_drag_edge) {
@@ -1473,6 +1480,8 @@ GanvCanvasImpl::port_event(GdkEvent* event, GanvPort* port)
 	static double control_start_y     = 0;
 	static float  control_start_value = 0;
 
+	gboolean selected = FALSE;
+
 	switch (event->type) {
 	case GDK_BUTTON_PRESS:
 		if (event->button.button == 1) {
@@ -1589,7 +1598,6 @@ GanvCanvasImpl::port_event(GdkEvent* event, GanvPort* port)
 		return true;
 
 	case GDK_ENTER_NOTIFY:
-		gboolean selected;
 		g_object_get(G_OBJECT(port), "selected", &selected, NULL);
 		if (!control_dragging && !selected) {
 			highlight_port(port, true);
@@ -1632,8 +1640,8 @@ GanvCanvasImpl::ports_joined(GanvPort* port1, GanvPort* port2)
 	highlight_port(port1, false);
 	highlight_port(port2, false);
 
-	GanvNode* src_node;
-	GanvNode* dst_node;
+	GanvNode* src_node = NULL;
+	GanvNode* dst_node = NULL;
 
 	if (port2->impl->is_input && !port1->impl->is_input) {
 		src_node = GANV_NODE(port1);
@@ -2122,7 +2130,8 @@ ganv_canvas_zoom_full(GanvCanvas* canvas)
 	if (canvas->impl->_items.empty())
 		return;
 
-	int win_width, win_height;
+	int win_width  = 0;
+	int win_height = 0;
 	GdkWindow* win = gtk_widget_get_window(
 		GTK_WIDGET(canvas->impl->_gcanvas));
 	gdk_window_get_size(win, &win_width, &win_height);
@@ -2159,7 +2168,8 @@ ganv_canvas_zoom_full(GanvCanvas* canvas)
 
 	ganv_canvas_set_zoom(canvas, new_zoom);
 
-	int scroll_x, scroll_y;
+	int scroll_x = 0;
+	int scroll_y = 0;
 	ganv_canvas_w2c(canvas->impl->_gcanvas,
 	                lrintf(left - pad), lrintf(bottom - pad),
 	                &scroll_x, &scroll_y);
@@ -2543,7 +2553,8 @@ ganv_canvas_get_zoom(const GanvCanvas* canvas)
 void
 ganv_canvas_move_contents_to(GanvCanvas* canvas, double x, double y)
 {
-	double min_x=HUGE_VAL, min_y=HUGE_VAL;
+	double min_x = HUGE_VAL;
+	double min_y = HUGE_VAL;
 	FOREACH_ITEM(canvas->impl->_items, i) {
 		const double x = GANV_ITEM(*i)->impl->x;
 		const double y = GANV_ITEM(*i)->impl->y;
@@ -2559,7 +2570,10 @@ ganv_canvas_arrange(GanvCanvas* canvas)
 #ifdef HAVE_AGRAPH
 	GVNodes nodes = canvas->impl->layout_dot((char*)"");
 
-	double least_x=HUGE_VAL, least_y=HUGE_VAL, most_x=0, most_y=0;
+	double least_x = HUGE_VAL;
+	double least_y = HUGE_VAL;
+	double most_x  = 0.0;
+	double most_y  = 0.0;
 
 	// Set numeric locale to POSIX for reading graphviz output with strtod
 	char* locale = strdup(setlocale(LC_NUMERIC, NULL));
@@ -2579,7 +2593,8 @@ ganv_canvas_arrange(GanvCanvas* canvas)
 		const double      cx    = lrint(strtod(x_str.c_str(), NULL) * dpp);
 		const double      cy    = lrint(strtod(y_str.c_str(), NULL) * dpp);
 
-		double w, h;
+		double w = 0.0;
+		double h = 0.0;
 		if (GANV_IS_BOX(i->first)) {
 			w = ganv_box_get_width(GANV_BOX(i->first));
 			h = ganv_box_get_height(GANV_BOX(i->first));
@@ -2618,7 +2633,8 @@ ganv_canvas_arrange(GanvCanvas* canvas)
 	//cerr << "CWH: " << _width << ", " << _height << endl;
 	//cerr << "GWH: " << graph_width << ", " << graph_height << endl;
 
-	double old_width, old_height;
+	double old_width  = 0.0;
+	double old_height = 0.0;
 	g_object_get(G_OBJECT(canvas),
 	             "width", &old_width,
 	             "height", &old_height,
@@ -2669,7 +2685,10 @@ ganv_canvas_export_image(GanvCanvas* canvas,
 	cairo_destroy(cr);
 
 	// Get draw extent
-	double x, y, w, h;
+	double x = 0.0;
+	double y = 0.0;
+	double w = 0.0;
+	double h = 0.0;
 	cairo_recording_surface_ink_extents(rec_surface, &x, &y, &w, &h);
 
 	// Create image surface with the appropriate size
@@ -2691,7 +2710,10 @@ ganv_canvas_export_image(GanvCanvas* canvas,
 	// Draw recording to image surface
 	cr = cairo_create(img);
 	if (draw_background) {
-		double r, g, b, a;
+		double r = 0.0;
+		double g = 0.0;
+		double b = 0.0;
+		double a = 0.0;
 		color_to_rgba(DEFAULT_BACKGROUND_COLOR, &r, &g, &b, &a);
 		cairo_set_source_rgba(cr, r, g, b, a);
 		cairo_rectangle(cr, 0, 0, w + 2 * pad, h + 2 * pad);
@@ -2954,11 +2976,16 @@ ganv_canvas_unrealize(GtkWidget* widget)
 static void
 scroll_to(GanvCanvas* canvas, int cx, int cy)
 {
-	int scroll_width, scroll_height;
-	int right_limit, bottom_limit;
-	int old_zoom_xofs, old_zoom_yofs;
-	int changed_x = FALSE, changed_y = FALSE;
-	int canvas_width, canvas_height;
+	int scroll_width  = 0;
+	int scroll_height = 0;
+	int right_limit   = 0;
+	int bottom_limit  = 0;
+	int old_zoom_xofs = 0;
+	int old_zoom_yofs = 0;
+	int changed_x     = 0;
+	int changed_y     = 0;
+	int canvas_width  = 0;
+	int canvas_height = 0;
 
 	canvas_width  = GTK_WIDGET(canvas)->allocation.width;
 	canvas_height = GTK_WIDGET(canvas)->allocation.height;
@@ -3092,11 +3119,11 @@ is_descendant(GanvItem* item, GanvItem* parent)
 int
 ganv_canvas_emit_event(GanvCanvas* canvas, GdkEvent* event)
 {
-	GdkEvent* ev;
-	gint      finished;
-	GanvItem* item;
-	GanvItem* parent;
-	guint     mask;
+	GdkEvent* ev       = NULL;
+	gint      finished = 0;
+	GanvItem* item     = NULL;
+	GanvItem* parent   = NULL;
+	guint     mask     = 0;
 
 	/* Perform checks for grabbed items */
 
@@ -3422,7 +3449,8 @@ pick_current_item(GanvCanvas* canvas, GdkEvent* event)
 	if (canvas->impl->pick_event.type != GDK_LEAVE_NOTIFY) {
 		/* these fields don't have the same offsets in both types of events */
 
-		double x, y;
+		double x = 0.0;
+		double y = 0.0;
 		if (canvas->impl->pick_event.type == GDK_ENTER_NOTIFY) {
 			x = canvas->impl->pick_event.crossing.x - canvas->impl->zoom_xofs;
 			y = canvas->impl->pick_event.crossing.y - canvas->impl->zoom_yofs;
@@ -3500,14 +3528,12 @@ pick_current_item(GanvCanvas* canvas, GdkEvent* event)
 static gint
 ganv_canvas_button(GtkWidget* widget, GdkEventButton* event)
 {
-	int mask;
-	int retval;
+	int mask   = 0;
+	int retval = FALSE;
 
 	g_return_val_if_fail(GANV_IS_CANVAS(widget), FALSE);
 	g_return_val_if_fail(event != NULL, FALSE);
 
-	retval = FALSE;
-
 	GanvCanvas* canvas = GANV_CANVAS(widget);
 
 	/*
@@ -3615,9 +3641,7 @@ ganv_canvas_key(GtkWidget* widget, GdkEventKey* event)
 	GanvCanvas* canvas = GANV_CANVAS(widget);
 
 	if (!ganv_canvas_emit_event(canvas, (GdkEvent*)event)) {
-		GtkWidgetClass* widget_class;
-
-		widget_class = GTK_WIDGET_CLASS(canvas_parent_class);
+		GtkWidgetClass* widget_class = GTK_WIDGET_CLASS(canvas_parent_class);
 
 		if (event->type == GDK_KEY_PRESS) {
 			if (widget_class->key_press_event) {
@@ -3689,19 +3713,18 @@ ganv_canvas_focus_out(GtkWidget* widget, GdkEventFocus* event)
 static void
 ganv_canvas_paint_rect(GanvCanvas* canvas, gint x0, gint y0, gint x1, gint y1)
 {
-	gint draw_x1, draw_y1;
-	gint draw_x2, draw_y2;
-	gint draw_width, draw_height;
-
 	g_return_if_fail(!canvas->impl->need_update);
 
-	draw_x1 = MAX(x0, canvas->layout.hadjustment->value - canvas->impl->zoom_xofs);
-	draw_y1 = MAX(y0, canvas->layout.vadjustment->value - canvas->impl->zoom_yofs);
-	draw_x2 = MIN(draw_x1 + GTK_WIDGET(canvas)->allocation.width, x1);
-	draw_y2 = MIN(draw_y1 + GTK_WIDGET(canvas)->allocation.height, y1);
+	gint draw_x1 =
+	    MAX(x0, canvas->layout.hadjustment->value - canvas->impl->zoom_xofs);
+	gint draw_y1 =
+	    MAX(y0, canvas->layout.vadjustment->value - canvas->impl->zoom_yofs);
+
+	gint draw_x2 = MIN(draw_x1 + GTK_WIDGET(canvas)->allocation.width, x1);
+	gint draw_y2 = MIN(draw_y1 + GTK_WIDGET(canvas)->allocation.height, y1);
 
-	draw_width  = draw_x2 - draw_x1;
-	draw_height = draw_y2 - draw_y1;
+	gint draw_width  = draw_x2 - draw_x1;
+	gint draw_height = draw_y2 - draw_y1;
 
 	if ((draw_width < 1) || (draw_height < 1)) {
 		return;
@@ -3716,18 +3739,25 @@ ganv_canvas_paint_rect(GanvCanvas* canvas, gint x0, gint y0, gint x1, gint y1)
 
 	cairo_t* cr = gdk_cairo_create(canvas->layout.bin_window);
 
-	double win_x, win_y;
+	double win_x = 0.0;
+	double win_y = 0.0;
 	ganv_canvas_window_to_world(canvas, 0, 0, &win_x, &win_y);
 	cairo_translate(cr, -win_x, -win_y);
 	cairo_scale(cr, canvas->impl->pixels_per_unit, canvas->impl->pixels_per_unit);
 
 	if (canvas->impl->root->object.flags & GANV_ITEM_VISIBLE) {
-		double wx1, wy1, ww, wh;
+		double wx1 = 0.0;
+		double wy1 = 0.0;
+		double ww  = 0.0;
+		double wh  = 0.0;
 		ganv_canvas_c2w(canvas, draw_x1, draw_y1, &wx1, &wy1);
 		ganv_canvas_c2w(canvas, draw_width, draw_height, &ww, &wh);
 
 		// Draw background
-		double r, g, b, a;
+		double r = 0.0;
+		double g = 0.0;
+		double b = 0.0;
+		double a = 0.0;
 		color_to_rgba(DEFAULT_BACKGROUND_COLOR, &r, &g, &b, &a);
 		cairo_set_source_rgba(cr, r, g, b, a);
 		cairo_rectangle(cr, wx1, wy1, ww, wh);
@@ -3889,8 +3919,10 @@ void
 ganv_canvas_set_scroll_region(GanvCanvas* canvas,
                               double x1, double y1, double x2, double y2)
 {
-	double wxofs, wyofs;
-	int    xofs, yofs;
+	double wxofs = 0.0;
+	double wyofs = 0.0;
+	int    xofs  = 0;
+	int    yofs  = 0;
 
 	g_return_if_fail(GANV_IS_CANVAS(canvas));
 
@@ -4076,7 +4108,10 @@ void
 ganv_canvas_request_redraw_w(GanvCanvas* canvas,
                              double x1, double y1, double x2, double y2)
 {
-	int cx1, cx2, cy1, cy2;
+	int cx1 = 0;
+	int cx2 = 0;
+	int cy1 = 0;
+	int cy2 = 0;
 	ganv_canvas_w2c(canvas, x1, y1, &cx1, &cy1);
 	ganv_canvas_w2c(canvas, x2, y2, &cx2, &cy2);
 	ganv_canvas_request_redraw_c(canvas, cx1, cy1, cx2, cy2);
diff --git a/src/box.c b/src/box.c
index 01814d1..b6f9a23 100644
--- a/src/box.c
+++ b/src/box.c
@@ -155,7 +155,10 @@ ganv_box_request_redraw(GanvItem*            item,
                         const GanvBoxCoords* coords,
                         gboolean             world)
 {
-	double x1, y1, x2, y2;
+	double x1 = 0.0;
+	double y1 = 0.0;
+	double x2 = 0.0;
+	double y2 = 0.0;
 	ganv_box_bounds_item(coords, &x1, &y1, &x2, &y2);
 
 	if (!world) {
@@ -268,11 +271,16 @@ ganv_box_draw(GanvItem* item,
 	double y2 = impl->coords.y2;
 	ganv_item_i2w_pair(item, &x1, &y1, &x2, &y2);
 
-	double dash_length, border_color, fill_color;
+	double dash_length  = 0.0;
+	double border_color = 0.0;
+	double fill_color   = 0.0;
 	ganv_node_get_draw_properties(
 		&box->node, &dash_length, &border_color, &fill_color);
 
-	double r, g, b, a;
+	double r = 0.0;
+	double g = 0.0;
+	double b = 0.0;
+	double a = 0.0;
 
 	for (int i = (impl->coords.stacked ? 1 : 0); i >= 0; --i) {
 		const double x = 0.0 - (STACKED_OFFSET * i);
@@ -314,7 +322,10 @@ ganv_box_point(GanvItem* item, double x, double y, GanvItem** actual_item)
 
 	*actual_item = NULL;
 
-	double x1, y1, x2, y2;
+	double x1 = 0.0;
+	double y1 = 0.0;
+	double x2 = 0.0;
+	double y2 = 0.0;
 	ganv_box_bounds_item(&impl->coords, &x1, &y1, &x2, &y2);
 
 	// Point is inside the box (distance 0)
@@ -351,7 +362,10 @@ ganv_box_is_within(const GanvNode* self,
                    double          x2,
                    double          y2)
 {
-	double bx1, by1, bx2, by2;
+	double bx1 = 0.0;
+	double by1 = 0.0;
+	double bx2 = 0.0;
+	double by2 = 0.0;
 	g_object_get(G_OBJECT(self),
 	             "x1", &bx1,
 	             "y1", &by1,
diff --git a/src/circle.c b/src/circle.c
index 723b229..4ec698b 100644
--- a/src/circle.c
+++ b/src/circle.c
@@ -298,13 +298,18 @@ ganv_circle_draw(GanvItem* item,
 	GanvCircle*        circle = GANV_CIRCLE(item);
 	GanvCirclePrivate* impl   = circle->impl;
 
-	double r, g, b, a;
+	double r = 0.0;
+	double g = 0.0;
+	double b = 0.0;
+	double a = 0.0;
 
 	double x = impl->coords.x;
 	double y = impl->coords.y;
 	ganv_item_i2w(item, &x, &y);
 
-	double dash_length, border_color, fill_color;
+	double dash_length  = 0.0;
+	double border_color = 0.0;
+	double fill_color   = 0.0;
 	ganv_node_get_draw_properties(
 		&circle->node, &dash_length, &border_color, &fill_color);
 
diff --git a/src/edge.c b/src/edge.c
index a1a5df2..a74546a 100644
--- a/src/edge.c
+++ b/src/edge.c
@@ -316,7 +316,10 @@ ganv_edge_update(GanvItem* item, int flags)
 	impl->old_coords = impl->coords;
 
 	// Get bounding box
-	double x1, x2, y1, y2;
+	double x1 = 0.0;
+	double x2 = 0.0;
+	double y1 = 0.0;
+	double y2 = 0.0;
 	ganv_edge_bounds(item, &x1, &y1, &x2, &y2);
 
 	// Ensure bounding box has non-zero area
@@ -359,7 +362,10 @@ ganv_edge_draw(GanvItem* item,
 	double dx    = src_x - dst_x;
 	double dy    = src_y - dst_y;
 
-	double r, g, b, a;
+	double r = 0.0;
+	double g = 0.0;
+	double b = 0.0;
+	double a = 0.0;
 	if (impl->highlighted) {
 		color_to_rgba(highlight_color(impl->color, 0x40), &r, &g, &b, &a);
 	} else {
diff --git a/src/group.c b/src/group.c
index 54a3765..5ef39f6 100644
--- a/src/group.c
+++ b/src/group.c
@@ -85,7 +85,7 @@ ganv_group_get_property(GObject* gobject, guint param_id,
 static void
 ganv_group_destroy(GtkObject* object)
 {
-	GanvGroup* group;
+	GanvGroup* group = NULL;
 
 	g_return_if_fail(GANV_IS_GROUP(object));
 
@@ -131,9 +131,9 @@ ganv_group_update(GanvItem* item, int flags)
 static void
 ganv_group_realize(GanvItem* item)
 {
-	GanvGroup* group;
-	GList*     list;
-	GanvItem*  i;
+	GanvGroup* group = NULL;
+	GList*     list  = NULL;
+	GanvItem*  i     = NULL;
 
 	group = GANV_GROUP(item);
 
@@ -151,9 +151,9 @@ ganv_group_realize(GanvItem* item)
 static void
 ganv_group_unrealize(GanvItem* item)
 {
-	GanvGroup* group;
-	GList*     list;
-	GanvItem*  i;
+	GanvGroup* group = NULL;
+	GList*     list  = NULL;
+	GanvItem*  i     = NULL;
 
 	group = GANV_GROUP(item);
 
@@ -171,9 +171,9 @@ ganv_group_unrealize(GanvItem* item)
 static void
 ganv_group_map(GanvItem* item)
 {
-	GanvGroup* group;
-	GList*     list;
-	GanvItem*  i;
+	GanvGroup* group = NULL;
+	GList*     list  = NULL;
+	GanvItem*  i     = NULL;
 
 	group = GANV_GROUP(item);
 
@@ -191,9 +191,9 @@ ganv_group_map(GanvItem* item)
 static void
 ganv_group_unmap(GanvItem* item)
 {
-	GanvGroup* group;
-	GList*     list;
-	GanvItem*  i;
+	GanvGroup* group = NULL;
+	GList*     list  = NULL;
+	GanvItem*  i     = NULL;
 
 	group = GANV_GROUP(item);
 
@@ -297,24 +297,21 @@ get_child_bounds(GanvItem* child, double* x1, double* y1, double* x2, double* y2
 static void
 ganv_group_bounds(GanvItem* item, double* x1, double* y1, double* x2, double* y2)
 {
-	GanvGroup* group;
-	GanvItem*  child;
-	GList*     list;
-	double     tx1, ty1, tx2, ty2;
-	double     minx = DBL_MAX;
-	double     miny = DBL_MAX;
-	double     maxx = DBL_MIN;
-	double     maxy = DBL_MIN;
-	int        set;
-
-	group = GANV_GROUP(item);
+	GanvGroup* group = GANV_GROUP(item);
+	GanvItem*  child = NULL;
+	GList*     list  = NULL;
+	double     tx1   = 0.0;
+	double     ty1   = 0.0;
+	double     tx2   = 0.0;
+	double     ty2   = 0.0;
+	double     minx  = DBL_MAX;
+	double     miny  = DBL_MAX;
+	double     maxx  = DBL_MIN;
+	double     maxy  = DBL_MIN;
+	int        set   = FALSE;
 
 	/* Get the bounds of the first visible item */
 
-	child = NULL; /* Unnecessary but eliminates a warning. */
-
-	set = FALSE;
-
 	for (list = group->impl->item_list; list; list = list->next) {
 		child = (GanvItem*)list->data;
 
@@ -395,8 +392,8 @@ ganv_group_add(GanvItem* parent, GanvItem* item)
 static void
 ganv_group_remove(GanvItem* parent, GanvItem* item)
 {
-	GanvGroup* group = GANV_GROUP(parent);
-	GList* children;
+	GanvGroup* group    = GANV_GROUP(parent);
+	GList*     children = NULL;
 
 	g_return_if_fail(GANV_IS_GROUP(group));
 	g_return_if_fail(GANV_IS_ITEM(item));
@@ -432,13 +429,9 @@ ganv_group_remove(GanvItem* parent, GanvItem* item)
 static void
 ganv_group_class_init(GanvGroupClass* klass)
 {
-	GObjectClass*   gobject_class;
-	GtkObjectClass* object_class;
-	GanvItemClass*  item_class;
-
-	gobject_class = (GObjectClass*)klass;
-	object_class  = (GtkObjectClass*)klass;
-	item_class    = (GanvItemClass*)klass;
+	GObjectClass*   gobject_class = (GObjectClass*)klass;
+	GtkObjectClass* object_class  = (GtkObjectClass*)klass;
+	GanvItemClass*  item_class    = (GanvItemClass*)klass;
 
 	group_parent_class = (GanvItemClass*)g_type_class_peek_parent(klass);
 
diff --git a/src/item.c b/src/item.c
index 06db304..fc5aac6 100644
--- a/src/item.c
+++ b/src/item.c
@@ -252,7 +252,7 @@ redraw_if_visible(GanvItem* item)
 static void
 ganv_item_dispose(GObject* object)
 {
-	GanvItem* item;
+	GanvItem* item = NULL;
 
 	g_return_if_fail(GANV_IS_ITEM(object));
 
@@ -517,8 +517,8 @@ ganv_item_i2w(GanvItem* item, double* x, double* y)
 	  g_return_if_fail(x != NULL);
 	  g_return_if_fail(y != NULL);*/
 
-	double off_x;
-	double off_y;
+	double off_x = 0.0;
+	double off_y = 0.0;
 	ganv_item_i2w_offset(item, &off_x, &off_y);
 
 	*x += off_x;
@@ -528,8 +528,8 @@ ganv_item_i2w(GanvItem* item, double* x, double* y)
 void
 ganv_item_i2w_pair(GanvItem* item, double* x1, double* y1, double* x2, double* y2)
 {
-	double off_x;
-	double off_y;
+	double off_x = 0.0;
+	double off_y = 0.0;
 	ganv_item_i2w_offset(item, &off_x, &off_y);
 
 	*x1 += off_x;
@@ -550,8 +550,8 @@ ganv_item_i2w_pair(GanvItem* item, double* x1, double* y1, double* x2, double* y
 void
 ganv_item_w2i(GanvItem* item, double* x, double* y)
 {
-	double off_x;
-	double off_y;
+	double off_x = 0.0;
+	double off_y = 0.0;
 	ganv_item_i2w_offset(item, &off_x, &off_y);
 
 	*x -= off_x;
@@ -652,8 +652,8 @@ boolean_handled_accumulator(GSignalInvocationHint* ihint,
 	(void)ihint;
 	(void)dummy;
 
-	gboolean continue_emission;
-	gboolean signal_handled;
+	gboolean continue_emission = FALSE;
+	gboolean signal_handled    = FALSE;
 
 	signal_handled = g_value_get_boolean(handler_return);
 	g_value_set_boolean(return_accu, signal_handled);
@@ -666,9 +666,7 @@ boolean_handled_accumulator(GSignalInvocationHint* ihint,
 static void
 ganv_item_class_init(GanvItemClass* klass)
 {
-	GObjectClass* gobject_class;
-
-	gobject_class = (GObjectClass*)klass;
+	GObjectClass* gobject_class = (GObjectClass*)klass;
 
 	item_parent_class = (GtkObjectClass*)g_type_class_peek_parent(klass);
 
diff --git a/src/module.c b/src/module.c
index e96932e..92ac3fe 100644
--- a/src/module.c
+++ b/src/module.c
@@ -167,7 +167,8 @@ measure(GanvModule* module, Metrics* m)
 {
 	memset(m, '\0', sizeof(Metrics));
 
-	double title_w, title_h;
+	double title_w = 0.0;
+	double title_h = 0.0;
 	title_size(module, &title_w, &title_h);
 
 	GanvCanvas*        canvas       = ganv_item_get_canvas(GANV_ITEM(module));
@@ -268,7 +269,8 @@ place_title(GanvModule* module, GanvDirection dir)
 	GanvBox*  box          = GANV_BOX(module);
 	GanvText* canvas_title = GANV_NODE(module)->impl->label;
 
-	double title_w, title_h;
+	double title_w = 0.0;
+	double title_h = 0.0;
 	title_size(module, &title_w, &title_h);
 
 	if (!canvas_title) {
@@ -294,7 +296,8 @@ resize_right(GanvModule* module)
 	Metrics m;
 	measure(module, &m);
 
-	double title_w, title_h;
+	double title_w = 0.0;
+	double title_h = 0.0;
 	title_size(module, &title_w, &title_h);
 
 	// Basic height contains title
@@ -370,7 +373,8 @@ resize_down(GanvModule* module)
 	Metrics m;
 	measure(module, &m);
 
-	double title_w, title_h;
+	double title_w = 0.0;
+	double title_h = 0.0;
 	title_size(module, &title_w, &title_h);
 
 	const double port_depth   = ganv_module_get_empty_port_depth(module);
@@ -821,7 +825,8 @@ ganv_module_embed(GanvModule* module,
 		return;
 	}
 
-	double title_w, title_h;
+	double title_w = 0.0;
+	double title_h = 0.0;
 	title_size(module, &title_w, &title_h);
 
 	impl->embed_item = ganv_item_new(
diff --git a/src/node.c b/src/node.c
index 81d10a6..f93222b 100644
--- a/src/node.c
+++ b/src/node.c
@@ -32,6 +32,7 @@
 #include <glib.h>
 #include <gtk/gtk.h>
 
+#include <math.h>
 #include <stddef.h>
 
 guint signal_moved;
@@ -490,9 +491,11 @@ ganv_node_default_event(GanvItem* item,
 	GanvCanvas* canvas = ganv_item_get_canvas(GANV_ITEM(node));
 
 	// FIXME: put these somewhere better
-	static double last_x, last_y;
-	static double drag_start_x, drag_start_y;
-	static gboolean dragging = FALSE;
+	static double   last_x       = NAN;
+	static double   last_y       = NAN;
+	static double   drag_start_x = NAN;
+	static double   drag_start_y = NAN;
+	static gboolean dragging     = FALSE;
 
 	switch (event->type) {
 	case GDK_ENTER_NOTIFY:
@@ -526,7 +529,7 @@ ganv_node_default_event(GanvItem* item,
 
 	case GDK_BUTTON_RELEASE:
 		if (dragging) {
-			gboolean selected;
+			gboolean selected = FALSE;
 			g_object_get(G_OBJECT(node), "selected", &selected, NULL);
 			ganv_canvas_ungrab_item(GANV_ITEM(node), event->button.time);
 			node->impl->grabbed = FALSE;
@@ -557,16 +560,16 @@ ganv_node_default_event(GanvItem* item,
 
 	case GDK_MOTION_NOTIFY:
 		if ((dragging && (event->motion.state & GDK_BUTTON1_MASK))) {
-			gboolean selected;
+			gboolean selected = FALSE;
 			g_object_get(G_OBJECT(node), "selected", &selected, NULL);
 
 			double new_x = event->motion.x;
 			double new_y = event->motion.y;
 
 			if (event->motion.is_hint) {
-				int t_x;
-				int t_y;
-				GdkModifierType state;
+				int             t_x   = 0;
+				int             t_y   = 0;
+				GdkModifierType state = (GdkModifierType)0;
 				gdk_window_get_pointer(event->motion.window, &t_x, &t_y, &state);
 				new_x = t_x;
 				new_y = t_y;
diff --git a/src/port.c b/src/port.c
index dcd3ac3..212b787 100644
--- a/src/port.c
+++ b/src/port.c
@@ -699,7 +699,7 @@ ganv_port_get_natural_width(const GanvPort* port)
 	if (ganv_canvas_get_direction(canvas) == GANV_DIRECTION_DOWN) {
 		w = ganv_module_get_empty_port_breadth(ganv_port_get_module(port));
 	} else if (label && (GANV_ITEM(label)->object.flags & GANV_ITEM_VISIBLE)) {
-		double label_w;
+		double label_w = 0.0;
 		g_object_get(port->box.node.impl->label, "width", &label_w, NULL);
 		w = label_w + (PORT_LABEL_HPAD * 2.0);
 	} else {
@@ -708,7 +708,7 @@ ganv_port_get_natural_width(const GanvPort* port)
 	if (port->impl->value_label &&
 	    (GANV_ITEM(port->impl->value_label)->object.flags
 	     & GANV_ITEM_VISIBLE)) {
-		double label_w;
+		double label_w = 0.0;
 		g_object_get(port->impl->value_label, "width", &label_w, NULL);
 		w += label_w + PORT_LABEL_HPAD;
 	}
diff --git a/src/text.c b/src/text.c
index 058d765..7e5a565 100644
--- a/src/text.c
+++ b/src/text.c
@@ -128,7 +128,8 @@ ganv_text_layout(GanvText* text)
 	cairo_font_options_destroy(opt);
 	pango_font_description_free(font);
 
-	int width, height;
+	int width  = 0;
+	int height = 0;
 	pango_layout_get_pixel_size(impl->layout, &width, &height);
 
 	impl->coords.width  = width;
@@ -255,14 +256,18 @@ ganv_text_point(GanvItem* item, double x, double y, GanvItem** actual_item)
 {
 	*actual_item = NULL;
 
-	double x1, y1, x2, y2;
+	double x1 = 0.0;
+	double y1 = 0.0;
+	double x2 = 0.0;
+	double y2 = 0.0;
 	ganv_text_bounds_item(item, &x1, &y1, &x2, &y2);
 	if ((x >= x1) && (y >= y1) && (x <= x2) && (y <= y2)) {
 		return 0.0;
 	}
 
 	// Point is outside the box
-	double dx, dy;
+	double dx = 0.0;
+	double dy = 0.0;
 
 	// Find horizontal distance to nearest edge
 	if (x < x1) {
@@ -305,7 +310,10 @@ ganv_text_draw(GanvItem* item,
 		ganv_text_layout(text);
 	}
 
-	double r, g, b, a;
+	double r = 0.0;
+	double g = 0.0;
+	double b = 0.0;
+	double a = 0.0;
 	color_to_rgba(impl->color, &r, &g, &b, &a);
 
 	cairo_set_source_rgba(cr, r, g, b, a);
diff --git a/src/widget.c b/src/widget.c
index e67a485..262aef3 100644
--- a/src/widget.c
+++ b/src/widget.c
@@ -142,7 +142,8 @@ recalc_bounds(GanvWidget* witem)
 	item->impl->x2 = witem->impl->cx + witem->impl->cwidth;
 	item->impl->y2 = witem->impl->cy + witem->impl->cheight;
 
-	int zoom_xofs, zoom_yofs;
+	int zoom_xofs = 0;
+	int zoom_yofs = 0;
 	ganv_canvas_get_zoom_offsets(item->impl->canvas, &zoom_xofs, &zoom_yofs);
 	if (witem->impl->widget) {
 		gtk_layout_move(GTK_LAYOUT(item->impl->canvas), witem->impl->widget,
@@ -172,7 +173,7 @@ ganv_widget_set_property(GObject*      object,
 	GanvWidget* witem       = GANV_WIDGET(object);
 	int         update      = FALSE;
 	int         calc_bounds = FALSE;
-	GObject*    obj;
+	GObject*    obj         = NULL;
 
 	switch (param_id) {
 	case PROP_WIDGET:
@@ -187,7 +188,8 @@ ganv_widget_set_property(GObject*      object,
 			witem->impl->destroy_id = g_signal_connect(obj, "destroy",
 			                                     G_CALLBACK(do_destroy),
 			                                     witem);
-			int zoom_xofs, zoom_yofs;
+			int zoom_xofs = 0;
+			int zoom_yofs = 0;
 			ganv_canvas_get_zoom_offsets(item->impl->canvas, &zoom_xofs, &zoom_yofs);
 
 			gtk_layout_put(GTK_LAYOUT(item->impl->canvas), witem->impl->widget,
@@ -352,7 +354,8 @@ ganv_widget_point(GanvItem* item, double x, double y, GanvItem** actual_item)
 
 	*actual_item = item;
 
-	double x1, y1;
+	double x1 = 0.0;
+	double y1 = 0.0;
 	ganv_canvas_c2w(item->impl->canvas, witem->impl->cx, witem->impl->cy, &x1, &y1);
 
 	const double pixels_per_unit = ganv_canvas_get_zoom(item->impl->canvas);
@@ -368,7 +371,7 @@ ganv_widget_point(GanvItem* item, double x, double y, GanvItem** actual_item)
 
 	/* Point is outside widget bounds */
 
-	double dx;
+	double dx = 0.0;
 	if (x < x1) {
 		dx = x1 - x;
 	} else if (x > x2) {
@@ -377,7 +380,7 @@ ganv_widget_point(GanvItem* item, double x, double y, GanvItem** actual_item)
 		dx = 0.0;
 	}
 
-	double dy;
+	double dy = 0.0;
 	if (y < y1) {
 		dy = y1 - y;
 	} else if (y > y2) {