diyac/layer.c

#define _POSIX_C_SOURCE 200112L
#include <wlr/util/log.h>
#include <stdlib.h>
#include <assert.h>
#include "layer.h"
#include "node.h"
#include "output.h"
#include "seat.h"

static void popup_handle_new_popup(struct wl_listener *listener, void *data);
static struct diyac_popup *create_layer_popup(struct wlr_xdg_popup *wlr_popup, struct wlr_scene_tree *parent);
static void process_keyboard_interactivity(struct diyac_layer_surface *layer)
{
    struct wlr_layer_surface_v1 *layer_surface = layer->scene_layer_surface->layer_surface;
    struct diyac_seat *seat = &layer->server->seat;

    if (layer_surface->current.keyboard_interactive && layer_surface->current.layer >= ZWLR_LAYER_SHELL_V1_LAYER_TOP)
    {
        /*
         * Give keyboard focus to surface if
         * - keyboard-interactivity is 'exclusive' or 'on-demand'; and
         * - surface is in top/overlay layers; and
         * - currently focused layer has a lower precedence
         *
         * In other words, when dealing with two surfaces with
         * exclusive/on-demand keyboard-interactivity (firstly the
         * currently focused 'focused_layer' and secondly the
         * 'layer_surface' for which we're just responding to a
         * map/commit event), the following logic applies:
         *
         * | focused_layer | layer_surface | who gets keyboard focus |
         * |---------------|---------------|-------------------------|
         * | overlay       | top           | focused_layer           |
         * | overlay       | overlay       | layer_surface           |
         * | top           | top           | layer_surface           |
         * | top           | overlay       | layer_surface           |
         */

        if (!seat->focused_layer || seat->focused_layer->current.layer <= layer_surface->current.layer)
        {
            diyac_seat_focus_layer(seat, layer_surface);
        }
    }
    else if (seat->focused_layer && !seat->focused_layer->current.keyboard_interactive)
    {
        /*
         * Clear focus if keyboard-interactivity has been set to
         * ZWLR_LAYER_SURFACE_V1_KEYBOARD_INTERACTIVITY_NONE
         */
        diyac_seat_focus_layer(seat, NULL);
    }
}
static void layer_surface_commit(struct wl_listener *listener, void *data)
{
    struct diyac_layer_surface *layer =
        wl_container_of(listener, layer, surface_commit);
    struct wlr_layer_surface_v1 *layer_surface =
        layer->scene_layer_surface->layer_surface;
    struct wlr_output *wlr_output =
        layer->scene_layer_surface->layer_surface->output;

    if (!wlr_output)
    {
        return;
    }

    uint32_t committed = layer_surface->current.committed;
    struct diyac_output *output = (struct diyac_output *)wlr_output->data;

    /* Process layer change */
    if (committed & WLR_LAYER_SURFACE_V1_STATE_LAYER)
    {
        wlr_scene_node_reparent(&layer->scene_layer_surface->tree->node,
                                output->layer_tree[layer_surface->current.layer]);
    }
    /* Process keyboard-interactivity change */
    if (committed & WLR_LAYER_SURFACE_V1_STATE_KEYBOARD_INTERACTIVITY)
    {
        wlr_log(WLR_INFO, "Process keyboard");
        process_keyboard_interactivity(layer);
    }

    if (committed || layer->mapped != layer_surface->surface->mapped)
    {
        layer->mapped = layer_surface->surface->mapped;
        diyac_output_update_usable_area(output);
        /*
         * Update cursor focus here to ensure we
         * enter a new/moved/resized layer surface.
         */
        // cursor_update_focus(layer->server);
        wlr_log(WLR_INFO, "update focus");
    }
}
static void
layer_surface_unmap(struct wl_listener *listener, void *data)
{
    struct diyac_layer_surface *layer = wl_container_of(listener, layer, unmap);
    struct wlr_layer_surface_v1 *layer_surface =
        layer->scene_layer_surface->layer_surface;
    if (layer_surface->output)
    {
        diyac_output_update_usable_area(layer_surface->output->data);
    }
    struct diyac_seat *seat = &layer->server->seat;
    if (seat->focused_layer == layer_surface) {
     diyac_seat_focus_layer(seat, NULL);
    }
}

static void layer_surface_map(struct wl_listener *listener, void *data)
{
    struct diyac_layer_surface *layer = wl_container_of(listener, layer, map);
    struct wlr_output *wlr_output =
        layer->scene_layer_surface->layer_surface->output;
    if (wlr_output)
    {
        diyac_output_update_usable_area(wlr_output->data);
    }
    /*
     * Since moving to the wlroots scene-graph API, there is no need to
     * call wlr_surface_send_enter() from here since that will be done
     * automatically based on the position of the surface and outputs in
     * the scene. See wlr_scene_surface_create() documentation.
     */

    process_keyboard_interactivity(layer);
}
static void layer_surface_node_destroy(struct wl_listener *listener, void *data)
{
    struct diyac_layer_surface *layer =
        wl_container_of(listener, layer, node_destroy);

    /*
     * TODO: Determine if this layer is being used by an exclusive client.
     * If it is, try and find another layer owned by this client to pass
     * focus to.
     */

    wl_list_remove(&layer->map.link);
    wl_list_remove(&layer->unmap.link);
    wl_list_remove(&layer->surface_commit.link);
    wl_list_remove(&layer->new_popup.link);
    wl_list_remove(&layer->output_destroy.link);
    wl_list_remove(&layer->node_destroy.link);
    free(layer);
}
static void layer_surface_output_destroy(struct wl_listener *listener, void *data)
{
    struct diyac_layer_surface *layer =
        wl_container_of(listener, layer, output_destroy);
    layer->scene_layer_surface->layer_surface->output = NULL;
    wlr_layer_surface_v1_destroy(layer->scene_layer_surface->layer_surface);
}
static void
popup_handle_destroy(struct wl_listener *listener, void *data)
{
    struct diyac_popup *popup = wl_container_of(listener, popup, destroy);
    wl_list_remove(&popup->destroy.link);
    wl_list_remove(&popup->new_popup.link);

    /* Usually already removed unless there was no commit at all */
    if (popup->commit.notify)
    {
        wl_list_remove(&popup->commit.link);
    }

    free(popup);
}

static void popup_handle_commit(struct wl_listener *listener, void *data)
{
    struct diyac_popup *popup =
        wl_container_of(listener, popup, commit);

    if (popup->wlr_popup->base->initial_commit)
    {
        wlr_xdg_popup_unconstrain_from_box(popup->wlr_popup, &popup->output_toplevel_sx_box);

        /* Prevent getting called over and over again */
        wl_list_remove(&popup->commit.link);
        popup->commit.notify = NULL;
    }
}
/* This popup's parent is a layer popup */
static void popup_handle_new_popup(struct wl_listener *listener, void *data)
{
    struct diyac_popup *popup =
        wl_container_of(listener, popup, new_popup);
    struct wlr_xdg_popup *wlr_popup = data;
    struct diyac_popup *new_popup = create_layer_popup(wlr_popup,
                                                 popup->scene_tree);
    new_popup->output_toplevel_sx_box = popup->output_toplevel_sx_box;
}

static struct diyac_popup *create_layer_popup(struct wlr_xdg_popup *wlr_popup, struct wlr_scene_tree *parent)
{
    wlr_log(WLR_INFO,
            "create_layer_popup: popup create");
    struct diyac_popup *popup = calloc(1, sizeof(*popup));
    popup->wlr_popup = wlr_popup;
    popup->scene_tree =
        wlr_scene_xdg_surface_create(parent, wlr_popup->base);
    if (!popup->scene_tree)
    {
        free(popup);
        return NULL;
    }
    diyac_node_descriptor_create(&popup->scene_tree->node,
                                 DIYAC_NODE_LAYER_POPUP, popup);

    popup->destroy.notify = popup_handle_destroy;
    wl_signal_add(&wlr_popup->base->events.destroy, &popup->destroy);

    popup->new_popup.notify = popup_handle_new_popup;
    wl_signal_add(&wlr_popup->base->events.new_popup, &popup->new_popup);

    popup->commit.notify = popup_handle_commit;
    wl_signal_add(&wlr_popup->base->surface->events.commit, &popup->commit);

    return popup;
}

/*
 * We move popups from the bottom to the top layer so that they are
 * rendered above views.
 */
static void move_popup_to_top_layer(struct diyac_layer_surface *toplevel,
                                    struct diyac_popup *popup)
{
    wlr_log(WLR_INFO,
            "move_popup_to_top_layer: popup notif");
    struct diyac_server *server = toplevel->server;
    struct wlr_output *wlr_output =
        toplevel->scene_layer_surface->layer_surface->output;
    struct diyac_output *output = (struct diyac_output *)wlr_output->data;
    struct wlr_box box = {0};
    wlr_output_layout_get_box(server->output_layout, wlr_output, &box);
    int lx = toplevel->scene_layer_surface->tree->node.x + box.x;
    int ly = toplevel->scene_layer_surface->tree->node.y + box.y;

    struct wlr_scene_node *node = &popup->scene_tree->node;
    wlr_scene_node_reparent(node, output->scenes.popup);
    /* FIXME: verify the whole tree should be repositioned */
    wlr_scene_node_set_position(&output->scenes.popup->node, lx, ly);
}

/* This popup's parent is a layer popup */
static void layer_popup_new(struct wl_listener *listener, void *data)
{
    wlr_log(WLR_INFO,
            "layer_popup_new: popup notif");
    struct diyac_layer_surface *toplevel =
        wl_container_of(listener, toplevel, new_popup);
    struct wlr_xdg_popup *wlr_popup = data;

    struct diyac_server *server = toplevel->server;
    struct wlr_scene_layer_surface_v1 *surface = toplevel->scene_layer_surface;
    struct diyac_output *output = surface->layer_surface->output->data;

    int lx, ly;
    wlr_scene_node_coords(&surface->tree->node, &lx, &ly);

    struct wlr_box output_box = {0};
    wlr_output_layout_get_box(server->output_layout,
                              output->wlr_output, &output_box);

    /*
     * Output geometry expressed in the coordinate system of the toplevel
     * parent of popup. We store this struct the lab_layer_popup struct
     * to make it easier to unconstrain children when we move popups from
     * the bottom to the top layer.
     */
    struct wlr_box output_toplevel_sx_box = {
        .x = output_box.x - lx,
        .y = output_box.y - ly,
        .width = output_box.width,
        .height = output_box.height,
    };
    struct diyac_popup *popup = create_layer_popup(wlr_popup, surface->tree);
    popup->output_toplevel_sx_box = output_toplevel_sx_box;

    if (surface->layer_surface->current.layer <= ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM)
    {
        move_popup_to_top_layer(toplevel, popup);
    }
}
void diyac_new_layer_surface(struct wl_listener *listener, void *data)
{
    struct diyac_server *server = wl_container_of(listener, server, new_layer_surface);
    struct wlr_layer_surface_v1 *layer_surface = data;

    if (!layer_surface->output)
    {
        struct wlr_output *output = wlr_output_layout_output_at(
            server->output_layout, server->seat.cursor->x,
            server->seat.cursor->y);
        if (!output)
        {
            wlr_log(WLR_INFO,
                    "No output available to assign layer surface");
            wlr_layer_surface_v1_destroy(layer_surface);
            return;
        }
        layer_surface->output = output;
    }

    struct diyac_layer_surface *surface = calloc(1, sizeof(*surface));

    struct diyac_output *output = layer_surface->output->data;

    struct wlr_scene_tree *selected_layer =
        output->layer_tree[layer_surface->current.layer];

    surface->scene_layer_surface = wlr_scene_layer_surface_v1_create(
        selected_layer, layer_surface);
    if (!surface->scene_layer_surface)
    {
        wlr_layer_surface_v1_destroy(layer_surface);
        wlr_log(WLR_ERROR, "could not create layer surface");
        return;
    }

    diyac_node_descriptor_create(&surface->scene_layer_surface->tree->node,
                                 DIYAC_NODE_LAYER_SURFACE, surface);

    surface->server = server;
    surface->scene_layer_surface->layer_surface = layer_surface;

    surface->surface_commit.notify = layer_surface_commit;
    wl_signal_add(&layer_surface->surface->events.commit,
                  &surface->surface_commit);

    surface->map.notify = layer_surface_map;
    wl_signal_add(&layer_surface->surface->events.map, &surface->map);

    surface->unmap.notify = layer_surface_unmap;
    wl_signal_add(&layer_surface->surface->events.unmap, &surface->unmap);

    surface->new_popup.notify = layer_popup_new;
    wl_signal_add(&layer_surface->events.new_popup, &surface->new_popup);

    surface->output_destroy.notify = layer_surface_output_destroy;
    wl_signal_add(&layer_surface->output->events.destroy,
                  &surface->output_destroy);

    surface->node_destroy.notify = layer_surface_node_destroy;
    wl_signal_add(&surface->scene_layer_surface->tree->node.events.destroy,
                  &surface->node_destroy);

    /*
     * Temporarily set the layer's current state to pending so that
     * it can easily be arranged.
     */
    struct wlr_layer_surface_v1_state old_state = layer_surface->current;
    layer_surface->current = layer_surface->pending;
    diyac_output_update_usable_area(output);
    layer_surface->current = old_state;
}

static void arrange_one_layer(const struct wlr_box *full_area, struct wlr_box *usable_area,
                              struct wlr_scene_tree *tree, bool exclusive)
{
    struct wlr_scene_node *node;
    wl_list_for_each(node, &tree->children, link)
    {
        struct diyac_layer_surface *surface = diyac_layer_surface_from_node(node);
        struct wlr_scene_layer_surface_v1 *scene = surface->scene_layer_surface;
        if (!!scene->layer_surface->current.exclusive_zone != exclusive)
        {
            continue;
        }
        wlr_scene_layer_surface_v1_configure(scene, full_area, usable_area);
    }
}

/*
 * To ensure outputs/views are left in a consistent state, this
 * function should be called ONLY from output_update_usable_area()
 * or output_update_all_usable_areas().
 */
void diyac_layers_arrange(struct diyac_output *output)
{
    assert(output);
    struct wlr_box full_area = {0};
    wlr_output_effective_resolution(output->wlr_output,
                                    &full_area.width, &full_area.height);
    struct wlr_box usable_area = full_area;
    struct diyac_server *server = output->server;
    struct wlr_scene_output *scene_output =
        wlr_scene_get_scene_output(server->scene, output->wlr_output);
    if (!scene_output)
    {
        wlr_log(WLR_DEBUG, "no wlr_scene_output");
        return;
    }

    for (int i = LAYER_TREE_SZ - 1; i >= 0; i--)
    {
        struct wlr_scene_tree *layer = output->layer_tree[i];

        /*
         * Process exclusive-zone clients before non-exclusive-zone
         * clients, so that the latter give way to the former regardless
         * of the order in which they were launched.
         *
         * Also start calculating the usable_area for exclusive-zone
         * clients from the Overlay layer down to the Background layer
         * to ensure that higher layers have a higher preference for
         * placement.
         *
         * The 'exclusive' boolean also matches -1 which means that
         * the layershell client wants to use the full screen rather
         * than the usable area.
         */
        arrange_one_layer(&full_area, &usable_area, layer, /* exclusive */ true);
    }

    for (size_t i = 0; i < LAYER_TREE_SZ; i++)
    {
        struct wlr_scene_tree *layer = output->layer_tree[i];
        arrange_one_layer(&full_area, &usable_area, layer, /* exclusive */ false);

        /* Set node position to account for output layout change */
        wlr_scene_node_set_position(&layer->node, scene_output->x, scene_output->y);
    }

    output->usable_area = usable_area;
}