From 9d234eab11681d45d7ec84463a9dcfae402172c6 Mon Sep 17 00:00:00 2001
From: Janis <janis@nirgendwo.xyz>
Date: Fri, 16 Dec 2022 15:44:14 +0100
Subject: [PATCH] selection math

---
 main.zig | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 89 insertions(+), 10 deletions(-)

diff --git a/main.zig b/main.zig
index 09721b8..c0e68a7 100644
--- a/main.zig
+++ b/main.zig
@@ -30,6 +30,24 @@ const Size = struct {
     }
 };
 
+const Selection = struct {
+    const Self = @This();
+
+    start: Point,
+    end: Point,
+
+    fn fromPoint(point: Point) Self {
+        return .{
+            .start = point,
+            .end = point,
+        };
+    }
+
+    fn asBox(self: Self) Box {
+        return Box.fromCorners(self.start, self.end);
+    }
+};
+
 const Box = struct {
     const Self = @This();
 
@@ -74,8 +92,8 @@ const Box = struct {
 
         const pos = Point{.x = left, .y = top,};
         const extents = Size{
-            .width = right - left,
-            .height = bot - top,
+            .width = @intCast(u32, right - left),
+            .height = @intCast(u32, bot - top),
         };
 
         return Self {
@@ -370,8 +388,29 @@ const Seat = struct {
     pointer: ?struct {
         pointer: *wl.Pointer,
         button_state: ?wl.Pointer.ButtonState = null,
+        selection: SelectionState = SelectionState.None(),
     } = null,
 
+
+    const SelectionTag = enum {
+        none,
+        pre,
+        updating,
+        post,
+    };
+
+    const SelectionState = union(SelectionTag) {
+
+        none: void,
+        pre: Point,
+        updating: Selection,
+        post: Box,
+
+        fn None() SelectionState {
+            return SelectionState.none;
+        }
+    };
+
     fn init(self: *Self, state: *State.Init) void {
         self.state = state;
 
@@ -381,8 +420,47 @@ const Seat = struct {
 
     fn pointerListener(pointer: *wl.Pointer, event: wl.Pointer.Event, self: *Self) void {
         _ = pointer;
-        _ = self;
-        _ = event;
+
+        std.debug.print("selection: {}\n", .{self.pointer.?.selection});
+
+        switch (event) {
+            .enter => {},
+            .leave => {},
+            .motion => |motion| {
+                const x = motion.surface_x.toInt();
+                const y = motion.surface_y.toInt();
+
+                const end = Point{.x = x, .y = y,};
+
+                switch (self.pointer.?.selection) {
+                    .pre => {
+                        self.pointer.?.selection = .{.updating = .{.start = end, .end = end}};
+                    },
+                    .updating => |*selection| {
+                        selection.end = end;
+                    },
+                    else => {},
+                }
+            },
+            .button => |button| {
+                switch (button.state) {
+                    .pressed => {
+                        self.pointer.?.selection = SelectionState{.pre = .{}};
+                    },
+                    .released => {
+                        switch (self.pointer.?.selection) {
+                            .updating => |selection| {
+                                const box = selection.asBox();
+                                self.pointer.?.selection = .{.post = box};
+                            },
+                            else => {},
+                        }
+                    },
+                    else => {},
+                }
+            },
+            else => {},
+        }
 
     }
 
@@ -440,12 +518,13 @@ const Seat = struct {
                 if (self.keyboard.?.xkb) |xkb_| {
                     const keysym = xkb.xkb_state_key_get_one_sym(xkb_.state, key.key + 8);
 
-                    const buf_len = 32;
-                    const buf = self.state.ally.alloc(u8, buf_len) catch null;
-                    if (buf) |buffer| {
-                        _ = xkb.xkb_keysym_get_name(keysym, @ptrCast([*c]u8, buffer), buf_len);
-                        std.debug.print("key: {s} {s}\n", .{buffer, if (key.state == .pressed) "pressed" else "released"});
-                    }
+                    // const buf_len = 32;
+                    // const buf = self.state.ally.alloc(u8, buf_len) catch null;
+                    // if (buf) |buffer| {
+                    //     _ = xkb.xkb_keysym_get_name(keysym, @ptrCast([*c]u8, buffer), buf_len);
+                    //     std.debug.print("key: {s} {s}\n", .{buffer, if (key.state == .pressed) "pressed" else "released"});
+                    // }
+
                     switch (key.state) {
                         .pressed => {
                             switch (keysym) {