anotherim-desktop/main/src/ui/util/scaling_image.vala
2020-10-27 16:05:30 +01:00

184 lines
7.3 KiB
Vala

using Gdk;
using Gtk;
namespace Dino.Ui {
class ScalingImage : Misc {
public int min_width { get; set; default = -1; }
public int target_width { get; set; default = -1; }
public int max_width { get; set; default = -1; }
public int min_height { get; set; default = -1; }
public int max_height { get; set; default = -1; }
private Pixbuf image;
private double image_ratio;
private int image_height = 0;
private int image_width = 0;
private int last_allocation_height = -1;
private int last_allocation_width = -1;
private int last_scale_factor = -1;
private Cairo.ImageSurface? cached_surface;
private static int8 use_image_surface = -1;
public void load(Pixbuf image) {
this.image = image;
this.image_ratio = ((double)image.height) / ((double)image.width);
this.image_height = image.height;
this.image_width = image.width;
queue_resize();
}
public override void dispose() {
base.dispose();
image = null;
cached_surface = null;
}
private void calculate_size(ref double exact_width, ref double exact_height) {
if (exact_width == -1 && exact_height == -1) {
if (target_width == -1) {
exact_width = ((double)image_width) / ((double)scale_factor);
exact_height = ((double)image_height) / ((double)scale_factor);
} else {
exact_width = target_width;
exact_height = exact_width * image_ratio;
}
} else if (exact_width != -1) {
exact_height = exact_width * image_ratio;
} else if (exact_height != -1) {
exact_width = exact_height / image_ratio;
} else {
if (exact_width * image_ratio > exact_height + scale_factor) {
exact_width = exact_height / image_ratio;
} else if (exact_height / image_ratio > exact_width + scale_factor) {
exact_height = exact_width * image_ratio;
}
}
if (max_width != -1 && exact_width > max_width) {
exact_width = max_width;
exact_height = exact_width * image_ratio;
}
if (max_height != -1 && exact_height > max_height) {
exact_height = max_height;
exact_width = exact_height / image_ratio;
}
if (exact_width < min_width) exact_width = min_width;
if (exact_height < min_height) exact_height = min_height;
}
public override void size_allocate(Allocation allocation) {
if (max_width != -1) allocation.width = int.min(allocation.width, max_width);
if (max_height != -1) allocation.height = int.min(allocation.height, max_height);
allocation.height = int.max(allocation.height, min_height);
allocation.width = int.max(allocation.width, min_width);
double exact_width = allocation.width, exact_height = allocation.height;
calculate_size(ref exact_width, ref exact_height);
base.size_allocate(allocation);
if (last_allocation_height != allocation.height || last_allocation_width != allocation.width || last_scale_factor != scale_factor) {
last_allocation_height = allocation.height;
last_allocation_width = allocation.width;
last_scale_factor = scale_factor;
cached_surface = null;
}
}
public override bool draw(Cairo.Context ctx_in) {
if (image == null) return false;
Cairo.Context ctx = ctx_in;
int width = this.get_allocated_width(), height = this.get_allocated_height(), base_factor = 1;
if (use_image_surface == -1) {
// TODO: detect if we have to buffer in image surface
use_image_surface = 1;
}
if (use_image_surface == 1) {
ctx_in.scale(1f / scale_factor, 1f / scale_factor);
if (cached_surface != null) {
ctx_in.set_source_surface(cached_surface, 0, 0);
ctx_in.paint();
ctx_in.set_source_rgb(0, 0, 0);
return true;
}
width *= scale_factor;
height *= scale_factor;
base_factor *= scale_factor;
cached_surface = new Cairo.ImageSurface(Cairo.Format.ARGB32, width, height);
ctx = new Cairo.Context(cached_surface);
}
double radius = 3 * base_factor;
double degrees = Math.PI / 180.0;
ctx.new_sub_path();
ctx.arc(width - radius, radius, radius, -90 * degrees, 0 * degrees);
ctx.arc(width - radius, height - radius, radius, 0 * degrees, 90 * degrees);
ctx.arc(radius, height - radius, radius, 90 * degrees, 180 * degrees);
ctx.arc(radius, radius, radius, 180 * degrees, 270 * degrees);
ctx.close_path();
ctx.clip();
Cairo.Surface buffer = sub_surface(ctx, width, height);
ctx.set_source_surface(buffer, 0, 0);
ctx.paint();
if (use_image_surface == 1) {
ctx_in.set_source_surface(ctx.get_target(), 0, 0);
ctx_in.paint();
ctx_in.set_source_rgb(0, 0, 0);
}
return true;
}
private Cairo.Surface sub_surface(Cairo.Context ctx, int width, int height) {
Cairo.Surface buffer = new Cairo.Surface.similar(ctx.get_target(), Cairo.Content.COLOR_ALPHA, width, height);
Cairo.Context bufctx = new Cairo.Context(buffer);
double w_scale = (double) width / image_width;
double h_scale = (double) height / image_height;
double scale = double.max(w_scale, h_scale);
bufctx.scale(scale, scale);
double x_off = 0, y_off = 0;
if (scale == h_scale) {
x_off = (width / scale - image_width) / 2.0;
} else {
y_off = (height / scale - image_height) / 2.0;
}
Gdk.cairo_set_source_pixbuf(bufctx, image, 0, 0);
bufctx.get_source().set_filter(Cairo.Filter.BILINEAR);
bufctx.paint();
bufctx.set_source_rgb(0, 0, 0);
return buffer;
}
public override void get_preferred_width(out int minimum_width, out int natural_width) {
minimum_width = int.max(0, min_width);
double exact_width = -1, exact_height = -1;
calculate_size(ref exact_width, ref exact_height);
natural_width = (int) Math.ceil(exact_width);
}
public override void get_preferred_height(out int minimum_height, out int natural_height) {
minimum_height = int.max(0, min_height);
double exact_width = -1, exact_height = -1;
calculate_size(ref exact_width, ref exact_height);
natural_height = (int) Math.ceil(exact_height);
}
public override void get_preferred_height_for_width(int width, out int minimum_height, out int natural_height) {
double exact_width = width, exact_height = -1;
calculate_size(ref exact_width, ref exact_height);
natural_height = (int) Math.ceil(exact_height);
minimum_height = natural_height;
}
public override void get_preferred_width_for_height(int height, out int minimum_width, out int natural_width) {
double exact_width = -1, exact_height = height;
calculate_size(ref exact_width, ref exact_height);
natural_width = (int) Math.ceil(exact_width);
minimum_width = natural_width;
}
public override SizeRequestMode get_request_mode() {
return SizeRequestMode.HEIGHT_FOR_WIDTH;
}
}
}