ngui: port some LVGL-based UI code from C to zig #20

the changes include lots of new code in ui/lvgl.zig and ui/widget.zig to work with LVGL directly from zig. in fact, some C code is moved from ui/c/ui.c to ui/xxx.zig.

in addition, a new module ui/widget.zig is where all custom UI elements will reside. at the moment it comprises of the ported topdrop and a new modal func. the latter is an alternative to LVGL's lv_msgbox popup.

as a practical example, the changes replace the power off confirmation popup with the new modal window: part of #5. here's how it looks like now; the white border lines around are the physical screen boundaries:

the changes include lots of new code in ui/lvgl.zig and ui/widget.zig to work with LVGL directly from zig. in fact, some C code is moved from ui/c/ui.c to ui/xxx.zig. in addition, a new module ui/widget.zig is where all custom UI elements will reside. at the moment it comprises of the ported topdrop and a new modal func. the latter is an alternative to LVGL's lv_msgbox popup. as a practical example, the changes replace the power off confirmation popup with the new modal window: part of https://git.qcode.ch/nakamochi/ndg/issues/5. here's how it looks like now; the white border lines around are the physical screen boundaries: ![image](/attachments/16ae90d3-835f-4aaf-b789-6351ecd48edc)

image.png

14 KiB

ah 💩 ci failed in https://woodpecker.qcode.ch/nakamochi/ndg/build/10/5 although compiles just fine or my machine. need to investigate.

the last forced push fixes a bug in indev deinit logic:

diff --git src/ui/lvgl.zig src/ui/lvgl.zig
index 2658532e..2f805efd 100644
--- src/ui/lvgl.zig
+++ src/ui/lvgl.zig
@@ -66,8 +66,8 @@ pub const TimerCallback = *const fn (timer: *LvTimer) callconv(.C) void;
 
 /// represents lv_indev_t in C, an input device such as touchscreen or a keyboard.
 pub const LvIndev = opaque {
-    pub fn first() *LvIndev {
-        return lv_indev_get_next(null).?; // there's always at least one indev
+    pub fn first() ?*LvIndev {
+        return lv_indev_get_next(null);
     }
 
     pub fn next(self: *LvIndev) ?*LvIndev {

the lv_indev_get_next(null) can actually return null during "go to standby" mode because all input devices are temporary deleted.

the last forced push fixes a bug in indev deinit logic: ```patch diff --git src/ui/lvgl.zig src/ui/lvgl.zig index 2658532e..2f805efd 100644 --- src/ui/lvgl.zig +++ src/ui/lvgl.zig @@ -66,8 +66,8 @@ pub const TimerCallback = *const fn (timer: *LvTimer) callconv(.C) void; /// represents lv_indev_t in C, an input device such as touchscreen or a keyboard. pub const LvIndev = opaque { - pub fn first() *LvIndev { - return lv_indev_get_next(null).?; // there's always at least one indev + pub fn first() ?*LvIndev { + return lv_indev_get_next(null); } pub fn next(self: *LvIndev) ?*LvIndev { ``` the `lv_indev_get_next(null)` can actually return null during "go to standby" mode because all input devices are temporary deleted.

actually merged with master at https://git.qcode.ch/nakamochi/ndg/commit/4297c139 but forgot to enable "manual merge detection" in the repo so gitea marked it as closed.

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ngui: port some LVGL-based UI code from C to zig #20