initial commit

cache.go

@@ -0,0 +1,101 @@
+package main
+
+// This file caches images in memory so we are not loading them from disk every time we need them
+// It also does the same for images that need to be grabbed from HTTP.
+
+import (
+	"github.com/diamondburned/gotk4/pkg/gdk/v4"
+	"github.com/diamondburned/gotk4/pkg/gtk/v4"
+	"crypto/sha256"
+	"fmt"
+	"net/http"
+	"io"
+	"os"
+)
+
+// global or app-level map/cache
+var textureCache = make(map[string]gdk.Paintabler)
+
+
+
+func getTexture(path string) gdk.Paintabler {
+	if tex, exists := textureCache[path]; exists {
+		return tex
+	}
+	tex, err := gdk.NewTextureFromFilename(path) // load once
+	if err != nil {
+		panic(err)
+	}
+	textureCache[path] = tex
+	return tex
+}
+
+func newPictureFromPath(path string) *gtk.Picture {
+	tex := getTexture(path)
+	img := gtk.NewPictureForPaintable(tex)
+	return img
+}
+
+func newImageFromPath(path string) *gtk.Image {
+	tex := getTexture(path)
+	img := gtk.NewImageFromPaintable(tex)
+	return img
+}
+
+func newPictureFromWeb(url string) *gtk.Picture {
+	// step 1: get a sha256 sum of the URL
+	sum := fmt.Sprintf("%x", sha256.Sum256([]byte(url)))
+
+	p, ok := textureCache[sum]
+	if ok {
+		return gtk.NewPictureForPaintable(p)
+	}
+
+	// step 2: download it
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil
+	}
+
+	// step 3: save it
+	err = os.WriteFile(sum, b, 0644)
+	if err != nil {
+		return nil
+	}
+
+	return newPictureFromPath(sum)
+}
+
+func newImageFromWeb(url string) *gtk.Image {
+	// step 1: get a sha256 sum of the URL
+	sum := fmt.Sprintf("%x", sha256.Sum256([]byte(url)))
+
+	p, ok := textureCache[sum]
+	if ok {
+		return gtk.NewImageFromPaintable(p)
+	}
+
+	// step 2: download it
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil
+	}
+
+	// step 3: save it
+	err = os.WriteFile(sum, b, 0644)
+	if err != nil {
+		return nil
+	}
+
+	return newImageFromPath(sum)
+}