Add a prototype of a directory view widget

1 files changed, 233 insertions, 0 deletions

diff --git a/fastiv-browser.c b/fastiv-browser.c
new file mode 100644
index 0000000..883a8b2
--- /dev/null
+++ b/fastiv-browser.c
@@ -0,0 +1,233 @@
+//
+// fastiv-browser.c: fast image viewer - filesystem browser widget
+//
+// Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+#include <math.h>
+
+#include "fastiv-browser.h"
+#include "fastiv-view.h"
+
+typedef struct entry Entry;
+
+struct entry {
+	char *filename;
+	cairo_surface_t *thumbnail;
+};
+
+static void
+entry_free(Entry *self)
+{
+	g_free(self->filename);
+	if (self->thumbnail)
+		cairo_surface_destroy(self->thumbnail);
+}
+
+// --- Boilerplate -------------------------------------------------------------
+
+struct _FastivBrowser {
+	GtkWidget parent_instance;
+
+	// TODO(p): We probably want to pre-arrange everything into rows.
+	//  - All rows are the same height.
+	GArray *entries;
+	int selected;
+};
+
+// TODO(p): For proper navigation, we need to implement GtkScrollable.
+G_DEFINE_TYPE_EXTENDED(FastivBrowser, fastiv_browser, GTK_TYPE_WIDGET, 0,
+	/* G_IMPLEMENT_INTERFACE(GTK_TYPE_SCROLLABLE,
+		fastiv_browser_scrollable_init) */)
+
+enum {
+	ITEM_ACTIVATED,
+	LAST_SIGNAL,
+};
+
+// Globals are, sadly, the canonical way of storing signal numbers.
+static guint browser_signals[LAST_SIGNAL];
+
+static void
+fastiv_browser_finalize(GObject *gobject)
+{
+	G_GNUC_UNUSED FastivBrowser *self = FASTIV_BROWSER(gobject);
+	G_OBJECT_CLASS(fastiv_browser_parent_class)->finalize(gobject);
+}
+
+static GtkSizeRequestMode
+fastiv_browser_get_request_mode(G_GNUC_UNUSED GtkWidget *widget)
+{
+	return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
+}
+
+static void
+fastiv_browser_get_preferred_width(GtkWidget *widget,
+	gint *minimum, gint *natural)
+{
+	G_GNUC_UNUSED FastivBrowser *self = FASTIV_BROWSER(widget);
+	// TODO(p): Set it to the width of the widget with one wide item within.
+	*minimum = *natural = 0;
+}
+
+static void
+fastiv_browser_get_preferred_height_for_width(GtkWidget *widget,
+	G_GNUC_UNUSED gint width, gint *minimum, gint *natural)
+{
+	G_GNUC_UNUSED FastivBrowser *self = FASTIV_BROWSER(widget);
+	// TODO(p): Re-layout, figure it out.
+	*minimum = *natural = 0;
+}
+
+static void
+fastiv_browser_realize(GtkWidget *widget)
+{
+	GtkAllocation allocation;
+	gtk_widget_get_allocation(widget, &allocation);
+
+	GdkWindowAttr attributes = {
+		.window_type = GDK_WINDOW_CHILD,
+		.x           = allocation.x,
+		.y           = allocation.y,
+		.width       = allocation.width,
+		.height      = allocation.height,
+
+		// Input-only would presumably also work (as in GtkPathBar, e.g.),
+		// but it merely seems to involve more work.
+		.wclass      = GDK_INPUT_OUTPUT,
+
+		.visual      = gtk_widget_get_visual(widget),
+		.event_mask  = gtk_widget_get_events(widget)
+			| GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK,
+	};
+
+	// We need this window to receive input events at all.
+	// TODO(p): See if input events bubble up to parents.
+	GdkWindow *window = gdk_window_new(gtk_widget_get_parent_window(widget),
+		&attributes, GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL);
+	gtk_widget_register_window(widget, window);
+	gtk_widget_set_window(widget, window);
+	gtk_widget_set_realized(widget, TRUE);
+}
+
+static gboolean
+fastiv_browser_draw(GtkWidget *widget, cairo_t *cr)
+{
+	G_GNUC_UNUSED FastivBrowser *self = FASTIV_BROWSER(widget);
+	if (!gtk_cairo_should_draw_window(cr, gtk_widget_get_window(widget)))
+		return TRUE;
+
+	GtkAllocation allocation;
+	gtk_widget_get_allocation(widget, &allocation);
+	gtk_render_background(gtk_widget_get_style_context(widget), cr,
+		0, 0, allocation.width, allocation.height);
+
+	const double row_height = 256;
+
+	gint occupied_width = 0, y = 0;
+	for (guint i = 0; i < self->entries->len; i++) {
+		const Entry *entry = &g_array_index(self->entries, Entry, i);
+		if (!entry->thumbnail)
+			continue;
+
+		int width = cairo_image_surface_get_width(entry->thumbnail);
+		int height = cairo_image_surface_get_height(entry->thumbnail);
+
+		double scale = row_height / height;
+		if (width * scale > 2 * row_height)
+			scale = 2 * row_height / width;
+
+		int projected_width = round(scale * width);
+		int projected_height = round(scale * height);
+
+		if (occupied_width != 0
+		 && occupied_width + projected_width > allocation.width) {
+			occupied_width = 0;
+			y += row_height;
+		}
+
+		cairo_save(cr);
+		cairo_translate(cr, occupied_width, y + row_height - projected_height);
+		cairo_scale(cr, scale, scale);
+		cairo_set_source_surface(cr, entry->thumbnail, 0, 0);
+		cairo_paint(cr);
+		cairo_restore(cr);
+
+		occupied_width += projected_width;
+	}
+	return TRUE;
+}
+
+static void
+fastiv_browser_class_init(FastivBrowserClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS(klass);
+	object_class->finalize = fastiv_browser_finalize;
+
+	GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
+	widget_class->get_request_mode = fastiv_browser_get_request_mode;
+	widget_class->get_preferred_width =
+		fastiv_browser_get_preferred_width;
+	widget_class->get_preferred_height_for_width =
+		fastiv_browser_get_preferred_height_for_width;
+	widget_class->realize = fastiv_browser_realize;
+	widget_class->draw = fastiv_browser_draw;
+
+	// TODO(p): Connect to this and emit it.
+	browser_signals[ITEM_ACTIVATED] =
+		g_signal_new("item-activated", G_TYPE_FROM_CLASS(klass),
+			0, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+
+	// TODO(p): Later override "screen_changed", recreate Pango layouts there,
+	// if we get to have any, or otherwise reflect DPI changes.
+	gtk_widget_class_set_css_name(widget_class, "fastiv-browser");
+}
+
+static void
+fastiv_browser_init(FastivBrowser *self)
+{
+	gtk_widget_set_can_focus(GTK_WIDGET(self), TRUE);
+
+	self->entries = g_array_new(FALSE, TRUE, sizeof(Entry));
+	g_array_set_clear_func(self->entries, (GDestroyNotify) entry_free);
+	self->selected = -1;
+}
+
+void
+fastiv_browser_load(FastivBrowser *self, const char *path)
+{
+	g_array_set_size(self->entries, 0);
+
+	// TODO(p): Use opendir(), in order to get file type directly.
+	GDir *dir = g_dir_open(path, 0, NULL);
+	if (!dir)
+		return;
+
+	const char *filename;
+	while ((filename = g_dir_read_name(dir))) {
+		if (!strcmp(filename, ".")
+		 || !strcmp(filename, ".."))
+			continue;
+
+		gchar *subpath = g_build_filename(path, filename, NULL);
+		g_array_append_val(self->entries, ((Entry) {
+			.thumbnail = fastiv_io_lookup_thumbnail(subpath),
+			.filename = subpath,
+		}));
+	}
+	g_dir_close(dir);
+
+	// TODO(p): Sort the entries.
+	gtk_widget_queue_draw(GTK_WIDGET(self));
+}