add reset button

src/main-scene.zig

@@ -4,6 +4,7 @@ const gui = @import("raygui");
 const std = @import("std");
 const roms = @import("./roms.zig");
 const GUILayout = @import("./gui-layout.zig");
+const VerticalLayout = @import("./vertical-layout.zig");
 const ROM = roms.ROM;
 
 const ChipContext = @import("chip.zig");
@@ -85,7 +86,11 @@ pub fn deinit(self: *Self) void {
 
 pub fn set_rom(self: *Self, index: i32) void {
     self.selected_rom_index = index;
-    const rom = rom_list[@intCast(index)];
+    self.reset_rom();
+}
+
+pub fn reset_rom(self: *Self) void {
+    const rom = rom_list[@intCast(self.selected_rom_index)];
     self.chip.reset();
     self.chip.set_memory(0x200, rom.data);
 }
@@ -175,6 +180,26 @@ fn GuiListViewMinWidth(allocator: Allocator, height: i32, items: []const []const
     return min_width;
 }
 
+pub fn getWindowBodyBounds(bounds: rl.Rectangle) rl.Rectangle {
+    const status_bar_height = 24; // defined as RAYGUI_WINDOWBOX_STATUSBAR_HEIGHT in raygui.h
+    const margin = 8;
+
+    return rl.Rectangle {
+        .x = bounds.x + margin,
+        .y = bounds.y + margin + status_bar_height,
+        .width = bounds.width - 2*margin,
+        .height = bounds.height - 2*margin - status_bar_height,
+    };
+}
+
+pub fn pushGuiWindowBox(layout: *GUILayout, bounds: rl.Rectangle, title: [*:0]const u8) bool {
+    const body = getWindowBodyBounds(bounds);
+    layout.push();
+    layout.translate(body.x, body.y);
+
+    return gui.GuiWindowBox(bounds, title) != 0;
+}
+
 pub fn drawGui(self: *Self, allocator: Allocator) !void {
     if (rl.IsKeyPressed(.KEY_TAB)) {
         self.is_gui_open = !self.is_gui_open;
@@ -182,8 +207,8 @@ pub fn drawGui(self: *Self, allocator: Allocator) !void {
 
     if (!self.is_gui_open) return;
 
-    var layout = GUILayout.init();
-    defer layout.deinit();
+    var window_layout = GUILayout.init();
+    defer window_layout.deinit();
 
     const screen_width: f32 = @floatFromInt(rl.GetScreenWidth());
     const screen_height: f32 = @floatFromInt(rl.GetScreenHeight());
@@ -194,37 +219,48 @@ pub fn drawGui(self: *Self, allocator: Allocator) !void {
         .a = 128,
     });
 
-    const window_width: f32 = 300;
-    const window_height: f32 = 100;
+    const window_width: f32 = 400;
+    const window_height: f32 = 200;
     const window = rl.Rectangle{
         .x = @trunc((screen_width-window_width)/2),
         .y = @trunc((screen_height-window_height)/2),
         .width = window_width,
         .height = window_height
     };
-    if (gui.GuiWindowBox(window, "CHIP-8 Settings") == 1) {
+    if (pushGuiWindowBox(&window_layout, window, "CHIP-8 Settings")) {
         self.is_gui_open = false;
     }
 
-    layout.push();
-    layout.translate(window.x, window.y);
+    var vertical_layout = VerticalLayout.init(4, getWindowBodyBounds(window));
 
-    const rom_list_names = try allocator.alloc([]const u8, rom_list.len);
-    defer allocator.free(rom_list_names);
-
-    for (0.., rom_list) |i, rom| {
-        rom_list_names[i] = rom.name;
+    if (gui.GuiButton(vertical_layout.row_sized(100, 24), "Reset") == 1) {
+        self.reset_rom();
     }
 
-    const list_height = 100;
-    const list_width = try GuiListViewMinWidth(allocator, list_height, rom_list_names) + 20;
-    _ = try GuiListView(
-        allocator,
-        layout.rect(10, 24, @floatFromInt(list_width), list_height),
-        rom_list_names,
-        &self.rom_list_scroll_index,
-        &self.selected_rom_index
-    );
+    _ = gui.GuiLabel(vertical_layout.row(16), "Current ROM:");
+    { // ROM list view
+        const rom_list_names = try allocator.alloc([]const u8, rom_list.len);
+        defer allocator.free(rom_list_names);
 
-    layout.pop();
+        for (0.., rom_list) |i, rom| {
+            rom_list_names[i] = rom.name;
+        }
+
+        const list_height = 100;
+        const list_width = try GuiListViewMinWidth(allocator, list_height, rom_list_names) + 20;
+        var selected_rom = self.selected_rom_index;
+        _ = try GuiListView(
+            allocator,
+            vertical_layout.row_sized(@floatFromInt(list_width), list_height),
+            rom_list_names,
+            &self.rom_list_scroll_index,
+            &selected_rom
+        );
+
+        if (selected_rom != self.selected_rom_index) {
+            self.set_rom(selected_rom);
+        }
+    }
+
+    window_layout.pop();
 }

src/vertical-layout.zig

@@ -0,0 +1,29 @@
+const Self = @This();
+const rl = @import("raylib");
+
+bounds: rl.Rectangle,
+gap: f32,
+used: f32,
+
+pub fn init(gap: f32, bounds: rl.Rectangle) Self {
+    return Self{
+        .bounds = bounds,
+        .gap = gap,
+        .used = 0
+    };
+}
+
+pub fn row_sized(self: *Self, width: f32, height: f32) rl.Rectangle {
+    const rect = rl.Rectangle{
+        .x = self.bounds.x,
+        .y = self.bounds.y + self.used,
+        .width = width,
+        .height = height,
+    };
+    self.used += height + self.gap;
+    return rect;
+}
+
+pub fn row(self: *Self, height: f32) rl.Rectangle {
+    return self.row_sized(self.bounds.width, height);
+}