1 files changed, 57 insertions, 5 deletions

diff --git a/src/main.c b/src/main.c
index 4a80d21..e65459b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,6 +14,7 @@
 #include "memory.h"
 #include "font.h"
 #include "menu.h"
+#include "tooltip.h"
 
 SDL_Window *window;
 SDL_Renderer *renderer;
@@ -34,6 +35,7 @@ static procfs_map *mappings = NULL;
 static int n_mappings = 0;
 
 static menu *current_menu = NULL;
+static tooltip current_tooltip = {0};
 
 static double get_scale() {
 	if (scale >= 1) {
@@ -307,6 +309,45 @@ static void update() {
 	} else {
 		mouse_held = false;
 	}
+
+	double x = mx, y = my;
+	absolute_pos(&x, &y);
+	uintptr_t addr = to_addr(x, y);
+	uintptr_t page_addr = addr - addr % PAGE_SIZE;
+	static uint8_t page_data[PAGE_SIZE];
+	if (read_mem(pages.fd, page_addr, page_data, PAGE_SIZE) == 0) {
+		uint8_t hover_byte = page_data[addr % PAGE_SIZE];
+		static char tooltip_buf[1024];
+		int n = snprintf(tooltip_buf, sizeof(tooltip_buf),
+			"%p\n0x%02x", addr, hover_byte
+		);
+		char *p = tooltip_buf + n;
+		if (hover_byte < 128 && hover_byte != 0) {
+			p = stpcpy(p, "\n\"");
+			int min, max;
+			for (min = addr % PAGE_SIZE; min > 0; min--) {
+				uint8_t next = page_data[min - 1];
+				if (next >= 128 || next == 0) break;
+			}
+			for (max = addr % PAGE_SIZE; max < PAGE_SIZE; max++) {
+				uint8_t cur = page_data[max];
+				if (cur >= 128 || cur == 0) break;
+			}
+			while (max - min > 64) {
+				if (max - addr % PAGE_SIZE > addr % PAGE_SIZE - min) {
+					max--;
+				} else {
+					min++;
+				}
+			}
+			memcpy(p, page_data + min, max - min);
+			p += max - min;
+			p = stpcpy(p, "\"");
+		}
+		set_tooltip_text(&current_tooltip, tooltip_buf);
+	} else {
+		set_tooltip_text(&current_tooltip, NULL);
+	}
 }
 
 static SDL_Texture *missing_texture();
@@ -377,6 +418,21 @@ static SDL_Texture *missing_texture() {
 	return tex;
 }
 
+static void show() {
+	SDL_GetWindowSize(window, &window_width, &window_height);
+	SDL_RenderClear(renderer);
+	show_pages();
+	SDL_RenderPresent(renderer);
+	if (current_menu) {
+		menu_render(current_menu);
+		hide_tooltip(&current_tooltip);
+	} else {
+		float mx, my;
+		SDL_GetMouseState(&mx, &my);
+		show_tooltip(&current_tooltip, mx, my);
+	}
+}
+
 static void main_loop() {
 	int last_time = 0, current_time = 0;
 	while (true) {
@@ -387,11 +443,7 @@ static void main_loop() {
 			}
 		}
 		update();
-		SDL_GetWindowSize(window, &window_width, &window_height);
-		SDL_RenderClear(renderer);
-		show_pages();
-		SDL_RenderPresent(renderer);
-		if (current_menu) menu_render(current_menu);
+		show();
 
 		last_time = current_time;
 		current_time = SDL_GetTicks();