refactor(display): use chrome devtools protocol (#38)

display/browser/main.go

@@ -0,0 +1,72 @@
+package browser
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/chromedp/chromedp"
+)
+
+var Browser BrowserType = BrowserType{}
+
+type BrowserType struct {
+	Ctx    context.Context
+	Cancel context.CancelFunc
+}
+
+func (b *BrowserType) Init() error {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("unable to determine user home directory: %w", err)
+	}
+	browserProfileDirPath := filepath.Join(home, ".local", "share", "plg-mudics", "browser-display")
+	if err := os.MkdirAll(browserProfileDirPath, os.ModePerm); err != nil {
+		return fmt.Errorf("failed to create local config directory: %w", err)
+	}
+
+	opts := []chromedp.ExecAllocatorOption{
+		chromedp.Flag("headless", false),
+		chromedp.Flag("app", "http://example.com"), // app mode prevents a few unwanted features of chrome, the start url is directly overwritten
+		chromedp.Flag("start-fullscreen", true),
+		chromedp.Flag("hide-scrollbars", true),
+		chromedp.Flag("allow-file-access-from-files", true),
+		chromedp.Flag("user-data-dir", browserProfileDirPath),
+		chromedp.Flag("autoplay-policy", "no-user-gesture-required"),
+	}
+
+	initCtx, _ := chromedp.NewExecAllocator(context.Background(), opts...)
+	b.Ctx, b.Cancel = chromedp.NewContext(initCtx)
+
+	return nil
+}
+
+func (b *BrowserType) OpenPage(url string) {
+	chromedp.Run(b.Ctx, chromedp.Navigate(url))
+}
+
+// Yes, we need that trick with creating a temp file and not directly sending html since
+// chrome only allows us to access local files via other local files
+func (b *BrowserType) OpenHTML(html string) error {
+	var err error
+
+	tempFile, err := os.CreateTemp("", "mudics-*.html")
+	if err != nil {
+		return fmt.Errorf("could not create tempfile: %w", err)
+	}
+	defer tempFile.Close()
+
+	_, err = tempFile.WriteString(html)
+	if err != nil {
+		return fmt.Errorf("could not write to tempfile: %w", err)
+	}
+
+	chromedp.Run(b.Ctx, chromedp.Navigate("file://"+tempFile.Name()))
+
+	return nil
+}
+
+func (b *BrowserType) OpenPDF(path string) {
+	b.OpenPage("file://" + path + "#toolbar=0&view=Fit")
+}