overhaul and improve performance of computed extents

Makefile

@@ -13,10 +13,10 @@ OBJS=$(patsubst $(SRC)/%.c, $(OBJ)/%.o, $(SRCS))
 DEPS=$(OBJS:%.o=%.d)
 
 
-all: CFLAGS+=-Og -ggdb -DNDEBUG
+all: CFLAGS+=-fsanitize=address -Og -ggdb
 all: $(BUILD) $(BIN)
 
-release: CFLAGS+=-O2 -flto=auto -DNDEBUG
+release: CFLAGS+=-O2 -flto=auto -DNDEBUG -ggdb
 release: clean $(BUILD) $(BIN)
 
 $(BIN): $(OBJS)

src/box-layout-node.c

@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <math.h>
 #include "box-layout-node.h"
+#include "node.h"
+#include "rect.h"
 
 int box_layout_handle(UINode *component, enum UIEvent ev, size_t d, void *p)
 {
@@ -27,38 +29,33 @@ int box_layout_handle(UINode *component, enum UIEvent ev, size_t d, void *p)
     int growing_widgets = 0;
     int current_index = 0;
 
-    if (ev == UI_EVENT_RELAYOUT || ev == UI_EVENT_GET_HEIGHT || ev == UI_EVENT_GET_WIDTH) {
+    if (ev == UI_EVENT_RELAYOUT || ev == UI_EVENT_GET_EXTENTS) {
         for (int i = 0; i < node->nodes_count; i++) {
             UINode *current = node->nodes[i];
             if (current->flags & UI_NODE_COMPONENT) continue;
 
-            double w = current->rect.w;
-            double h = current->rect.h;
-            if (current->width_policy == UI_SIZE_POLICY_DYNAMIC) {
-                node_dispatch(current, UI_EVENT_GET_WIDTH, 0, &w);
-                current->rect.w = w;
-            }
-            if (current->height_policy == UI_SIZE_POLICY_DYNAMIC) {
-                node_dispatch(current, UI_EVENT_GET_HEIGHT, 0, &h);
-                current->rect.h = h;
-            }
+            UIRect current_rect = node_get_computed_rect(current);
+
+            current->rect.w = current_rect.w;
+            current->rect.h = current_rect.h;
+
             if (is_horizontal) {
-                if (h > maximum_secondary_position) {
-                    maximum_secondary_position = h;
+                if (current_rect.h > maximum_secondary_position) {
+                    maximum_secondary_position = current_rect.h;
                 }
                 if (current->width_policy == UI_SIZE_POLICY_GROW) {
                     growing_widgets++;
                 } else {
-                    size += w;
+                    size += current_rect.w;
                 }
             } else {
-                if (w > maximum_secondary_position) {
-                    maximum_secondary_position = w;
+                if (current_rect.w > maximum_secondary_position) {
+                    maximum_secondary_position = current_rect.w;
                 }
                 if (current->height_policy == UI_SIZE_POLICY_GROW) {
                     growing_widgets++;
                 } else {
-                    size += h;
+                    size += current_rect.h;
                 }
             }
             if (current_index) {
@@ -70,18 +67,14 @@ int box_layout_handle(UINode *component, enum UIEvent ev, size_t d, void *p)
         maximum_secondary_position += is_horizontal ? margin_top + margin_bottom : margin_left + margin_right;
         size += is_vertical ? margin_top + margin_bottom : margin_left + margin_right;
 
-        if (ev == UI_EVENT_GET_WIDTH) {
-            *(double*)p = is_horizontal ? size : maximum_secondary_position;
-            return 1;
+        if (ev == UI_EVENT_GET_EXTENTS) {
+            ((UIRect*)p)->w = is_horizontal ? size : maximum_secondary_position;
+            ((UIRect*)p)->h = is_vertical ? size : maximum_secondary_position;
+            return UI_NODE_COMPUTED_EXTENTS_OK;
         }
-        if (ev == UI_EVENT_GET_HEIGHT) {
-            *(double*)p = is_vertical ? size : maximum_secondary_position;
-            return 1;
-        }
-
 
         // we can distribute growing layout children only if we have a fixed sized policy in the layout primary direction
-        bool is_fixed_for_primary_direction = (is_horizontal && node->width_policy != UI_SIZE_POLICY_DYNAMIC) || (is_vertical && node->height_policy != UI_SIZE_POLICY_DYNAMIC);
+        bool is_fixed_for_primary_direction = (is_horizontal && node->width_policy != UI_SIZE_POLICY_COMPUTED) || (is_vertical && node->height_policy != UI_SIZE_POLICY_COMPUTED);
         double primary_direction = is_horizontal ? node->rect.w - margin_left - margin_right : node->rect.h - margin_top - margin_bottom;
         bool distributes_growing_widgets = growing_widgets && is_fixed_for_primary_direction;
         double size_per_growing_widget = 0;
@@ -95,7 +88,7 @@ int box_layout_handle(UINode *component, enum UIEvent ev, size_t d, void *p)
             }
         }
 
-        bool is_fixed_for_secondary_direction = (is_horizontal && node->height_policy != UI_SIZE_POLICY_DYNAMIC) || (is_vertical && node->width_policy != UI_SIZE_POLICY_DYNAMIC);
+        bool is_fixed_for_secondary_direction = (is_horizontal && node->height_policy != UI_SIZE_POLICY_COMPUTED) || (is_vertical && node->width_policy != UI_SIZE_POLICY_COMPUTED);
         double secondary_direction = is_horizontal ? node->rect.h - margin_top - margin_bottom : node->rect.w - margin_left - margin_right;
         // if our layout secondary direction is fixed, we set the maximum known secondary position to it
         if (is_fixed_for_secondary_direction) {

src/main.c

@@ -125,20 +125,18 @@ int app_handle(struct UINode *node, void *data, int event_type, size_t d, void *
                 UIScrollableNode *scroll = scrollable_new(scroll_container, NULL);
                 UINode *buttons = node_new(scroll_container, "buttons");
                 buttons->width_policy = UI_SIZE_POLICY_GROW;
-                buttons->height_policy = UI_SIZE_POLICY_DYNAMIC;
+                buttons->height_policy = UI_SIZE_POLICY_COMPUTED;
                 scroll->target = buttons;
 
                 box_layout_new(buttons, UI_DIRECTION_VERTICAL);
 
-                for (int i = 0; i < 10000; i++) {
+                for (int i = 0; i < 3; i++) {
                     UINode *button = node_new(buttons, "button");
                     state_background_node_new(button, UIPurple600, UIPurple700, UIPurple800, 6.0);
                     text_node_new(button, state->font, UINeutral50, "button");
                     dispatcher_new(button, UI_EVENT_UNPRESSED, INCREMENT_COUNT, state, app_handle);
                     button->width_policy = UI_SIZE_POLICY_GROW;
                 }
-
-                printf("%d\n", buttons->last_component_index);
             }
 
             break;

src/node.c

@@ -6,6 +6,24 @@
 typedef struct UIWindow UIWindow;
 int window_invalidate_node(UIWindow *window, UINode *node);
 
+UIRect node_get_computed_rect(UINode *node) {
+    UIRect rect = node->rect;
+    UIRect extents = node->rect;
+
+    if (!node->cached_computed_extents && (node->width_policy == UI_SIZE_POLICY_COMPUTED || node->height_policy == UI_SIZE_POLICY_COMPUTED)) {
+        if (node_dispatch(node, UI_EVENT_GET_EXTENTS, 0, &extents) == UI_NODE_COMPUTED_EXTENTS_CACHED) {
+            // Whoever returned UI_NODE_COMPUTED_EXTENTS_CACHED has the responsibility to set
+            // cached_computed_extents back to false when the cache is no longer valid.
+            node->cached_computed_extents = true;
+        }
+    }
+
+    rect.w = node->width_policy == UI_SIZE_POLICY_COMPUTED ? extents.w : rect.w;
+    rect.h = node->height_policy == UI_SIZE_POLICY_COMPUTED ? extents.h : rect.h;
+
+    return rect;
+}
+
 int node_send(UINode *node, enum UIEvent ev, size_t d, void *p)
 {
     if (node->flags & UI_NODE_DISABLED) {
@@ -36,7 +54,7 @@ int node_dispatch(UINode *node, enum UIEvent ev, size_t d, void *p)
         }
         if (node->nodes[i]->flags & UI_NODE_COMPONENT) {
             component_index = i;
-            result = node_dispatch(node->nodes[i], ev, d, p);
+            result = node_send(node->nodes[i], ev, d, p);
             if (result) break;
         }
     }
@@ -78,11 +96,12 @@ void node_init(UINode *node)
     node->nodes_count = 0;
     node->nodes_capacity = 0;
     node->flags = 0;
-    node->width_policy = UI_SIZE_POLICY_DYNAMIC;
-    node->height_policy = UI_SIZE_POLICY_DYNAMIC;
+    node->width_policy = UI_SIZE_POLICY_COMPUTED;
+    node->height_policy = UI_SIZE_POLICY_COMPUTED;
     node->handle = NULL;
     node->handle_proto = NULL;
     node->last_component_index = UI_NODE_LAST_COMPONENT_INDEX_NONE;
+    node->cached_computed_extents = false;
 }
 
 void node_free(UINode *node)

src/node.h

@@ -6,11 +6,12 @@
 #include "rect.h"
 #include <cairo.h>
 
+#define UI_NODE_COMPUTED_EXTENTS_OK (1)
+#define UI_NODE_COMPUTED_EXTENTS_CACHED (2)
 enum UIEvent {
     UI_EVENT_REPAINT,
     UI_EVENT_RELAYOUT,
-    UI_EVENT_GET_WIDTH,
-    UI_EVENT_GET_HEIGHT,
+    UI_EVENT_GET_EXTENTS,
     UI_EVENT_HOVERED,
     UI_EVENT_UNHOVERED,
     UI_EVENT_PRESSED,
@@ -26,7 +27,7 @@ enum UIEvent {
 };
 
 enum UISizePolicy {
-    UI_SIZE_POLICY_DYNAMIC,
+    UI_SIZE_POLICY_COMPUTED,
     UI_SIZE_POLICY_GROW,
     UI_SIZE_POLICY_FIXED,
     UI_SIZE_POLICY_STATIC
@@ -56,11 +57,13 @@ typedef struct UINode {
     enum UISizePolicy width_policy;
     enum UISizePolicy height_policy;
     int last_component_index;
+    bool cached_computed_extents;
 
     int (*handle)(struct UINode *node, enum UIEvent ev, size_t d, void *p);
     int (*handle_proto)(struct UINode *node, enum UIEvent ev, size_t d, void *p);
 } UINode;
 
+UIRect node_get_computed_rect(UINode *node);
 int node_send(UINode *node, enum UIEvent ev, size_t d, void *p);
 int node_dispatch(UINode *node, enum UIEvent ev, size_t d, void *p);
 UINode *node_by_point(UINode *root, double x, double y);

src/scrollable-node.c

@@ -1,5 +1,7 @@
 #include "scrollable-node.h"
 #include "node.h"
+#include "rect.h"
+#include "window.h"
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -42,26 +44,16 @@ int scrollable_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
             if (n->y_scroll > scroll_end) {
                 n->y_scroll = scroll_end;
             }
-            node_request_relayout(n->node.parent);
+            target->rect.x = n->x_scroll ? -n->x_scroll : 0;
+            target->rect.y = n->y_scroll ? -n->y_scroll : 0;
+            window_invalidate_node(node->window, node);
             break;
         }
         case UI_EVENT_RELAYOUT: {
-            double w = target->rect.w;
-            double h = target->rect.h;
-            if (target->width_policy == UI_SIZE_POLICY_DYNAMIC) {
-                node_dispatch(target, UI_EVENT_GET_WIDTH, 0, &w);
-                target->rect.w = w;
-            } else if (target->width_policy == UI_SIZE_POLICY_GROW) {
-                target->rect.w = node->parent->rect.w;
-            }
-            if (target->height_policy == UI_SIZE_POLICY_DYNAMIC) {
-                node_dispatch(target, UI_EVENT_GET_HEIGHT, 0, &h);
-                target->rect.h = h;
-            } else if (target->height_policy == UI_SIZE_POLICY_GROW) {
-                target->rect.h = node->parent->rect.h;
-            }
-            target->rect.x = n->x_scroll ? -n->x_scroll : 0;
-            target->rect.y = n->y_scroll ? -n->y_scroll : 0;
+            UIRect rect = {0};
+            node_dispatch(target, UI_EVENT_GET_EXTENTS, 0, &rect);
+            target->rect.w = target->width_policy == UI_SIZE_POLICY_GROW ? node->parent->rect.w : rect.w;
+            target->rect.h = target->height_policy == UI_SIZE_POLICY_GROW ? node->parent->rect.h : rect.h;
             node_dispatch(target, UI_EVENT_RELAYOUT, 0, NULL);
             break;
         }

src/text-node.c

@@ -4,6 +4,7 @@
 #include "node.h"
 #include "pango/pango-layout.h"
 #include "pango/pango-types.h"
+#include "rect.h"
 #include "text-node.h"
 
 UITextNode *text_node_new(UINode *parent, PangoFontDescription *desc, UIRGBA color, char *text)
@@ -17,9 +18,6 @@ UITextNode *text_node_new(UINode *parent, PangoFontDescription *desc, UIRGBA col
     n->color = color;
     n->caret_index = -1;
     n->caret_node = NULL;
-    n->computed_dimensions_invalid = true;
-    n->computed_text_width = 0;
-    n->computed_text_height = 0;
     n->node.text = "text";
     n->node.handle_proto = text_node_handle;
     node_attach(parent, (UINode*)n);
@@ -50,7 +48,7 @@ int text_node_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
             n->layout = layout;
             n->pending_text = NULL;
         }
-        n->computed_dimensions_invalid = true;
+        node->parent->cached_computed_extents = false;
     }
 
     switch (ev) {
@@ -63,28 +61,21 @@ int text_node_handle(UINode *node, enum UIEvent ev, size_t d, void *p)
             cairo_fill(n->node.drw);
             break;
         }
-        case UI_EVENT_GET_WIDTH: /* through */
-        case UI_EVENT_GET_HEIGHT: {
-            if (n->computed_dimensions_invalid) {
-                int w, h = 0;
-                pango_layout_get_size(n->layout, &w, &h);
-                n->computed_text_width = pango_units_to_double(w);
-                n->computed_text_height = pango_units_to_double(h);
-                n->computed_dimensions_invalid = false;
+        case UI_EVENT_GET_EXTENTS: {
+            if (!n->layout) {
+                break;
             }
-            if (ev == UI_EVENT_GET_WIDTH) {
-                *(double*)p = n->computed_text_width;
-            }
-            if (ev == UI_EVENT_GET_HEIGHT) {
-                *(double*)p = n->computed_text_height;
-            }
-            break;
+            int w, h = 0;
+            pango_layout_get_size(n->layout, &w, &h);
+
+            ((UIRect*)p)->w = pango_units_to_double(w);
+            ((UIRect*)p)->h = pango_units_to_double(h);
+            return UI_NODE_COMPUTED_EXTENTS_CACHED;
         }
         case UI_EVENT_RELAYOUT: {
             if (!n->layout) {
                 break;
             }
-            pango_cairo_update_layout(n->node.drw, n->layout);
             if (n->caret_index >= 0) {
                 if (!n->caret_node) {
                     n->caret_node = node_new(&n->node, "caret");

src/text-node.h

@@ -15,9 +15,6 @@ typedef struct UITextNode {
     UIRGBA color;
     ssize_t caret_index;
     UINode *caret_node;
-    double computed_text_width;
-    double computed_text_height;
-    bool computed_dimensions_invalid;
 } UITextNode;
 
 int text_node_handle(UINode *node, enum UIEvent ev, size_t d, void *p);

src/window.c

@@ -428,7 +428,7 @@ static void window_process_xcb_event(UIWindow *window, xcb_generic_event_t *even
                 node_dispatch(window->root, UI_EVENT_RELAYOUT, 0, NULL);
                 window_invalidate_node(window, window->root);
 #ifdef _UI_DEBUG
-                node_dump(window->root, 0);
+                //node_dump(window->root, 0);
 #endif
             }
             end_clock();
@@ -497,12 +497,14 @@ static void window_process_xcb_event(UIWindow *window, xcb_generic_event_t *even
                     }
                 }
 
-                UINode *n = node;
-                while (n) {
-                    if (node_dispatch(n, ui_event, state, &delta) > 0) {
-                        break;
+                if (!(ui_event == UI_EVENT_SCROLL && !state)) {
+                    UINode *n = node;
+                    while (n) {
+                        if (node_dispatch(n, ui_event, state, &delta) > 0) {
+                            break;
+                        }
+                        n = n->parent;
                     }
-                    n = n->parent;
                 }
 
                 if (ui_event == UI_EVENT_BUTTON_LEFT_UPDATE) {