inaban

layers.c (10399B)

// Copyright 2019 Drew DeVault
// Copyright 2019-2020 Inaban Authors <https://hacktivis.me/git/inaban>
// SPDX-License-Identifier: BSD-3-Clause
#include "layers.h"

#include "server.h"

#include <stdlib.h>
#include <string.h>
#include <wayland-server.h>
#include <wlr/types/wlr_layer_shell_v1.h>

static void
apply_exclusive(struct wlr_box *usable_area,
                uint32_t anchor,
                int32_t exclusive,
                int32_t margin_top,
                int32_t margin_right,
                int32_t margin_bottom,
                int32_t margin_left)
{
	if(exclusive <= 0)
	{
		return;
	}
	struct
	{
		uint32_t anchors;
		int *positive_axis;
		int *negative_axis;
		int margin;
	} edges[] = {
	    {
	        .anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
	                   ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP,
	        .positive_axis = &usable_area->y,
	        .negative_axis = &usable_area->height,
	        .margin        = margin_top,
	    },
	    {
	        .anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
	                   ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
	        .positive_axis = NULL,
	        .negative_axis = &usable_area->height,
	        .margin        = margin_bottom,
	    },
	    {
	        .anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
	                   ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
	        .positive_axis = &usable_area->x,
	        .negative_axis = &usable_area->width,
	        .margin        = margin_left,
	    },
	    {
	        .anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
	                   ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
	        .positive_axis = NULL,
	        .negative_axis = &usable_area->width,
	        .margin        = margin_right,
	    },
	};
	for(size_t i = 0; i < sizeof(edges) / sizeof(edges[0]); ++i)
	{
		if((anchor & edges[i].anchors) == edges[i].anchors)
		{
			if(edges[i].positive_axis)
			{
				*edges[i].positive_axis += exclusive + edges[i].margin;
			}
			if(edges[i].negative_axis)
			{
				*edges[i].negative_axis -= exclusive + edges[i].margin;
			}
		}
	}
}

static void
arrange_layer(struct wlr_output *output,
              struct wl_list *list /* struct *inaban_layer_surface */,
              struct wlr_box *usable_area,
              bool exclusive)
{
	struct inaban_layer_surface *inaban_surface;
	struct wlr_box full_area = {0};
	wlr_output_effective_resolution(output, &full_area.width, &full_area.height);
	wl_list_for_each_reverse(inaban_surface, list, link)
	{
		struct wlr_layer_surface_v1 *layer       = inaban_surface->layer_surface;
		struct wlr_layer_surface_v1_state *state = &layer->current;
		if(exclusive != (state->exclusive_zone > 0))
		{
			continue;
		}
		struct wlr_box bounds;
		if(state->exclusive_zone == -1)
		{
			bounds = full_area;
		}
		else
		{
			bounds = *usable_area;
		}
		struct wlr_box box = {.width = state->desired_width, .height = state->desired_height};
		// Horizontal axis
		const uint32_t both_horiz =
		    ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
		if((state->anchor & both_horiz) && box.width == 0)
		{
			box.x     = bounds.x;
			box.width = bounds.width;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT))
		{
			box.x = bounds.x;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT))
		{
			box.x = bounds.x + (bounds.width - box.width);
		}
		else
		{
			box.x = bounds.x + ((bounds.width / 2) - (box.width / 2));
		}
		// Vertical axis
		const uint32_t both_vert =
		    ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
		if((state->anchor & both_vert) && box.height == 0)
		{
			box.y      = bounds.y;
			box.height = bounds.height;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP))
		{
			box.y = bounds.y;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM))
		{
			box.y = bounds.y + (bounds.height - box.height);
		}
		else
		{
			box.y = bounds.y + ((bounds.height / 2) - (box.height / 2));
		}
		// Margin
		if((state->anchor & both_horiz) == both_horiz)
		{
			box.x += state->margin.left;
			box.width -= state->margin.left + state->margin.right;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT))
		{
			box.x += state->margin.left;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT))
		{
			box.x -= state->margin.right;
		}
		if((state->anchor & both_vert) == both_vert)
		{
			box.y += state->margin.top;
			box.height -= state->margin.top + state->margin.bottom;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP))
		{
			box.y += state->margin.top;
		}
		else if((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM))
		{
			box.y -= state->margin.bottom;
		}
		if(box.width < 0 || box.height < 0)
		{
			// TODO: Bubble up a protocol error?
			wlr_layer_surface_v1_close(layer);
			continue;
		}

		// Apply
		inaban_surface->geo = box;
		apply_exclusive(usable_area,
		                state->anchor,
		                state->exclusive_zone,
		                state->margin.top,
		                state->margin.right,
		                state->margin.bottom,
		                state->margin.left);
		wlr_layer_surface_v1_configure(layer, box.width, box.height);
	}
}

void
arrange_layers(struct inaban_output *output)
{
	struct wlr_box usable_area = {0};
	wlr_output_effective_resolution(output->wlr_output, &usable_area.width, &usable_area.height);

	// Arrange exclusive surfaces from top->bottom
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY], &usable_area, true);
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &usable_area, true);
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM], &usable_area, true);
	arrange_layer(output->wlr_output,
	              &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
	              &usable_area,
	              true);

	// Arrange non-exlusive surfaces from top->bottom
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY], &usable_area, false);
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &usable_area, false);
	arrange_layer(
	    output->wlr_output, &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM], &usable_area, false);
	arrange_layer(output->wlr_output,
	              &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
	              &usable_area,
	              false);

	// Find topmost keyboard interactive layer, if such a layer exists
	uint32_t layers_above_shell[] = {
	    ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY,
	    ZWLR_LAYER_SHELL_V1_LAYER_TOP,
	};
	size_t nlayers = sizeof(layers_above_shell) / sizeof(layers_above_shell[0]);
	struct inaban_layer_surface *layer, *topmost = NULL;
	for(size_t i = 0; i < nlayers; ++i)
	{
		wl_list_for_each_reverse(layer, &output->layers[layers_above_shell[i]], link)
		{
			if(layer->layer_surface->current.keyboard_interactive)
			{
				topmost = layer;
				break;
			}
		}
		if(topmost != NULL)
		{
			break;
		}
	}

	// TODO: Focus topmost layer
}

static void
handle_output_destroy(struct wl_listener *listener, void *data)
{
	struct inaban_layer_surface *layer = wl_container_of(listener, layer, output_destroy);
	layer->layer_surface->output       = NULL;
	wl_list_remove(&layer->output_destroy.link);
	wlr_layer_surface_v1_close(layer->layer_surface);
}

static void
handle_surface_commit(struct wl_listener *listener, void *data)
{
	struct inaban_layer_surface *layer         = wl_container_of(listener, layer, surface_commit);
	struct wlr_layer_surface_v1 *layer_surface = layer->layer_surface;
	struct wlr_output *wlr_output              = layer_surface->output;
	if(wlr_output != NULL)
	{
		struct inaban_output *output = wlr_output->data;
		arrange_layers(output);
	}
}

static void
handle_destroy(struct wl_listener *listener, void *data)
{
	struct inaban_layer_surface *layer = wl_container_of(listener, layer, destroy);
	wl_list_remove(&layer->link);
	wl_list_remove(&layer->destroy.link);
	wl_list_remove(&layer->map.link);
	wl_list_remove(&layer->surface_commit.link);
	if(layer->layer_surface->output)
	{
		wl_list_remove(&layer->output_destroy.link);
		arrange_layers((struct inaban_output *)layer->layer_surface->output->data);
	}
	free(layer);
}

static void
handle_map(struct wl_listener *listener, void *data)
{
	struct wlr_layer_surface_v1 *layer_surface = data;
	wlr_surface_send_enter(layer_surface->surface, layer_surface->output);
}

void
server_new_layer_surface(struct wl_listener *listener, void *data)
{
	struct inaban_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->cursor->x, server->cursor->y);
		layer_surface->output = output;
	}

	struct inaban_output *output                = layer_surface->output->data;
	struct inaban_layer_surface *inaban_surface = calloc(1, sizeof(struct inaban_layer_surface));
	if(!inaban_surface)
	{
		return;
	}
	inaban_surface->layer_surface = layer_surface;
	layer_surface->data           = inaban_surface;
	inaban_surface->server        = server;

	inaban_surface->surface_commit.notify = handle_surface_commit;
	wl_signal_add(&layer_surface->surface->events.commit, &inaban_surface->surface_commit);
	inaban_surface->output_destroy.notify = handle_output_destroy;
	wl_signal_add(&layer_surface->output->events.destroy, &inaban_surface->output_destroy);
	inaban_surface->destroy.notify = handle_destroy;
	wl_signal_add(&layer_surface->events.destroy, &inaban_surface->destroy);
	inaban_surface->map.notify = handle_map;
	wl_signal_add(&layer_surface->events.map, &inaban_surface->map);
	// TODO: popups

	// TODO: Listen for subsurfaces
	wl_list_insert(&output->layers[layer_surface->layer], &inaban_surface->link);
	// Temporarily set the layer's current state to client_pending
	// So that we can easily arrange it
	struct wlr_layer_surface_v1_state old_state = layer_surface->current;
	layer_surface->current                      = layer_surface->client_pending;
	arrange_layers(output);
	layer_surface->current = old_state;
}