Implement TreeView (aka TreeWidget)

src/main.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const sdl = @import("sdl.zig");
 const ttf = @import("ttf.zig");
+const dirent = @cImport(@cInclude("dirent.h"));
 
 const Ui = struct {
     window: sdl.Window,
@@ -9,7 +10,7 @@ const Ui = struct {
     uiFont: ttf.Font,
     codeFont: ttf.Font,
 
-    treeWidget: TreeWidget,
+    treeWidget: TreeView,
 
     pub fn init() !Ui {
         try sdl.init();
@@ -20,7 +21,7 @@ const Ui = struct {
         var uiFont = try ttf.Font.init("/usr/share/fonts/ubuntu/Ubuntu-R.ttf", 16);
         var codeFont = try ttf.Font.init("/usr/share/fonts/TTF/Cascadia.ttf", 16);
 
-        var treeWidget = TreeWidget.init();
+        var treeWidget = TreeView.init();
 
         return Ui{
             .window = window,
@@ -45,44 +46,120 @@ const Ui = struct {
         sdl.quit();
     }
 
-    pub fn update(self: Ui) !void {
+    pub fn update(self: *Ui) !void {
         while (sdl.Event.poll()) |event| {
             var type_ = event.type_();
             // std.debug.warn("event: {}\n", .{@tagName(type_)});
 
             switch (type_) {
                 .Quit => return error.Exiting,
+                .MouseMotion => {
+                    var motion = event.mouseMotion().?;
+                    self.treeWidget.mouseMotion(motion);
+                },
                 else => {},
             }
         }
     }
 
-    pub fn render(self: Ui) !void {
+    pub fn render(self: *Ui) !void {
         try self.renderer.setDrawColor(.{ .r = 30, .g = 30, .b = 30 });
         try self.renderer.clear();
 
-        try self.treeWidget.render(self);
+        try self.treeWidget.render(self.*);
 
         self.renderer.present();
     }
 };
 
-const TreeWidget = struct {
-    pub fn init() TreeWidget {
-        return .{};
+const TreeView = struct {
+    const Entry = struct {
+        name: []const u8,
+        texture: ?sdl.Texture = null,
+        y: i32,
+        width: i32 = 0,
+        height: i32 = 0,
+
+        highlighted: bool = false,
+
+        fn prerender(self: *Entry, ui: Ui) !void {
+            var surface = try ui.uiFont.renderBlended(self.name, .{ .r = 255, .g = 255, .b = 255 });
+            self.texture = try ui.renderer.createTextureFromSurface(surface);
+            self.width = surface.width();
+            self.height = surface.height();
+
+            // We don't need the surface anymore.
+            surface.deinit();
         }
 
-    pub fn deinit(self: TreeWidget) void {}
+        pub fn render(self: *Entry, ui: Ui) !void {
+            if (self.texture == null) {
+                try self.prerender(ui);
+            }
 
-    pub fn render(self: TreeWidget, ui: Ui) !void {
-        var surface = try ui.uiFont.renderBlended("Hello world", .{ .r = 255, .g = 255, .b = 255 });
-        defer surface.deinit();
+            if (self.highlighted) {
+                try ui.renderer.setDrawColor(.{ .r = 42, .g = 45, .b = 46 });
+                try ui.renderer.fillRect(sdl.Rect{ .x = 0, .y = self.y, .w = 200, .h = 25 });
+            }
 
-        var texture = try ui.renderer.createTextureFromSurface(surface);
-        defer texture.deinit();
+            var y = @divTrunc(25 - self.height, 2);
+            var dst = sdl.Rect{ .x = 10, .y = self.y + y, .w = self.width, .h = self.height };
+            try ui.renderer.copy(self.texture.?, null, dst);
+        }
 
-        var dst = sdl.Rect{ .w = surface.width(), .h = surface.height() };
-        try ui.renderer.copy(texture, null, dst);
+        pub fn mouseMotion(self: *Entry, event: sdl.MouseMotionEvent) void {
+            self.highlighted = event.y > self.y and event.y < self.y + 20;
+        }
+    };
+
+    cursorHand: *sdl.c.SDL_Cursor,
+    count: u64 = 0,
+
+    // Temporary, std.heap.c_allocator was broken, so this for now
+    entries: [256]Entry = undefined,
+
+    pub fn init() TreeView {
+        var cursorHand = sdl.c.SDL_CreateSystemCursor(@intToEnum(sdl.c.SDL_SystemCursor, sdl.c.SDL_SYSTEM_CURSOR_HAND)).?;
+        sdl.c.SDL_SetCursor(cursorHand);
+        var self = TreeView{ .cursorHand = cursorHand };
+
+        self.refresh() catch unreachable;
+        return self;
+    }
+
+    pub fn deinit(self: TreeView) void {
+        sdl.c.SDL_FreeCursor(self.cursorHand);
+        for (self.entries[0..self.count]) |entry| {
+            if (entry.texture) |texture| {
+                texture.deinit();
+            }
+        }
+    }
+
+    pub fn render(self: *TreeView, ui: Ui) !void {
+        try ui.renderer.setDrawColor(.{ .r = 38, .g = 38, .b = 38 });
+        try ui.renderer.fillRect(sdl.Rect{ .x = 0, .y = 0, .w = 200, .h = 720 });
+
+        for (self.entries[0..self.count]) |*entry, i| {
+            try entry.render(ui);
+        }
+    }
+
+    pub fn refresh(self: *TreeView) !void {
+        var dir = try std.fs.cwd().openDir("./", .{ .iterate = true });
+        var iterator = dir.iterate();
+        var index: u31 = 0;
+        while (try iterator.next()) |file| {
+            self.entries[index] = Entry{ .name = file.name, .y = index * 25 + 10 };
+            index += 1;
+        }
+        self.count = index;
+    }
+
+    pub fn mouseMotion(self: *TreeView, event: sdl.MouseMotionEvent) void {
+        for (self.entries[0..self.count]) |*entry, i| {
+            entry.mouseMotion(event);
+        }
     }
 };
 

src/sdl.zig

@@ -84,6 +84,13 @@ pub const Renderer = struct {
             return error.SdlError;
         }
     }
+
+    pub fn fillRect(self: Renderer, rect: ?Rect) !void {
+        var dst = if (rect) |inner| &inner.c() else null;
+        if (c.SDL_RenderFillRect(self.renderer, dst) != 0) {
+            return error.SdlError;
+        }
+    }
 };
 
 pub const Texture = struct {
@@ -238,6 +245,17 @@ pub const EventType = enum(u32) {
     _,
 };
 
+pub const MouseMotionEvent = struct {
+    timestamp: u32,
+    windowId: u32,
+    which: u32,
+    state: u32,
+    x: i32,
+    y: i32,
+    xrel: i32,
+    yrel: i32,
+};
+
 pub const Event = struct {
     event: c.SDL_Event,
 
@@ -252,4 +270,22 @@ pub const Event = struct {
     pub fn type_(self: Event) EventType {
         return @intToEnum(EventType, self.event.type);
     }
+
+    pub fn mouseMotion(self: Event) ?MouseMotionEvent {
+        if (self.type_() != .MouseMotion) {
+            return null;
+        }
+
+        var inner = self.event.motion;
+        return MouseMotionEvent{
+            .timestamp = inner.timestamp,
+            .windowId = inner.windowID,
+            .which = inner.which,
+            .state = inner.state,
+            .x = inner.x,
+            .y = inner.y,
+            .xrel = inner.xrel,
+            .yrel = inner.yrel,
+        };
+    }
 };

src/ttf.zig

@@ -36,7 +36,7 @@ pub const Font = struct {
         c.TTF_CloseFont(self.font);
     }
 
-    pub fn renderBlended(self: Font, text: [:0]const u8, color: sdl.Color) !sdl.Surface {
+    pub fn renderBlended(self: Font, text: []const u8, color: sdl.Color) !sdl.Surface {
         var cText = @ptrCast([*c]const u8, text);
         if (c.TTF_RenderUTF8_Blended(self.font, cText, @bitCast(c.SDL_Color, color))) |surface| {
             return sdl.Surface{ .surface = @ptrCast(*sdl.c.SDL_Surface, surface) };