Fix file dialog and drag-and-drop loading issues

File dialog improvements:
- Add video file filters (*.mp4, *.mkv, etc.) so files are visible
- Add "All Files" filter as fallback
- Make dialog modal with Cancel button
- Improve usability with proper MIME type filtering

Drag-and-drop improvements:
- Use net/url.Parse for proper URL decoding (%20 for spaces, etc.)
- Handle file:// URIs correctly with localhost stripping
- Add comprehensive debug logging throughout load chain

Debug logging added to:
- uriToPath() - shows URI parsing
- loadIntoPane() - tracks load progress and MPV errors
- drag-data-received - shows received URIs
- file dialog - logs selected files

These changes should fix both file navigation in dialogs and
drag-and-drop video loading from file managers.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

cmd/gtkplayer/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"net/url"
 	"path/filepath"
 	"strings"
 	"time"
@@ -222,10 +223,41 @@ func buildControls(win *gtk.Window, left, right *pane) *gtk.Box {
 }
 
 func chooseAndLoad(win *gtk.Window, p *pane) {
-	dlg, _ := gtk.FileChooserDialogNewWith1Button("Open Video", win, gtk.FILE_CHOOSER_ACTION_OPEN, "Open", gtk.RESPONSE_ACCEPT)
+	dlg, _ := gtk.FileChooserDialogNewWith2Buttons(
+		"Open Video",
+		win,
+		gtk.FILE_CHOOSER_ACTION_OPEN,
+		"Cancel", gtk.RESPONSE_CANCEL,
+		"Open", gtk.RESPONSE_ACCEPT,
+	)
+	dlg.SetModal(true)
+
+	// Add file filter for video files
+	filter, _ := gtk.FileFilterNew()
+	filter.SetName("Video Files")
+	filter.AddMimeType("video/*")
+	filter.AddPattern("*.mp4")
+	filter.AddPattern("*.mkv")
+	filter.AddPattern("*.avi")
+	filter.AddPattern("*.mov")
+	filter.AddPattern("*.webm")
+	filter.AddPattern("*.flv")
+	filter.AddPattern("*.wmv")
+	filter.AddPattern("*.m4v")
+	filter.AddPattern("*.mpg")
+	filter.AddPattern("*.mpeg")
+	dlg.AddFilter(filter)
+
+	// Add "All Files" filter as fallback
+	allFilter, _ := gtk.FileFilterNew()
+	allFilter.SetName("All Files")
+	allFilter.AddPattern("*")
+	dlg.AddFilter(allFilter)
+
 	if resp := dlg.Run(); resp == gtk.RESPONSE_ACCEPT {
 		filename := dlg.GetFilename()
 		if filename != "" {
+			log.Printf("Selected file: %s", filename)
 			loadIntoPane(p, filename)
 		}
 	}
@@ -233,15 +265,21 @@ func chooseAndLoad(win *gtk.Window, p *pane) {
 }
 
 func loadIntoPane(p *pane, filename string) {
+	log.Printf("loadIntoPane: filename=%q", filename)
 	if !ensurePaneReady(p) {
+		log.Printf("loadIntoPane: pane not ready")
 		return
 	}
 	p.path = filename
 	p.id = getOrAddVideoID(filename)
+	log.Printf("loadIntoPane: calling mpv loadfile command")
 	if err := p.mpv.Command("loadfile", filename, "replace"); err != nil {
-		log.Printf("loadfile %s: %v", filename, err)
+		log.Printf("loadfile %s: ERROR: %v", filename, err)
+	} else {
+		log.Printf("loadfile %s: success", filename)
 	}
 	_ = p.mpv.SetPropertyBool("pause", false)
+	log.Printf("loadIntoPane: complete")
 }
 
 func metaSummary(a, b *pane) string {
@@ -312,10 +350,13 @@ func setupDragDest(targetPane *pane, left, right *pane) {
 			}
 		}()
 		if data == nil {
+			log.Printf("drag-data-received: data is nil")
 			return
 		}
 
+		log.Printf("drag-data-received: got data")
 		uris := parseURIs(data)
+		log.Printf("drag-data-received: parsed URIs: %v", uris)
 		for _, u := range uris {
 			if u == "" {
 				continue
@@ -377,10 +418,26 @@ func uriToPath(u string) string {
 	if u == "" {
 		return ""
 	}
-	// text/uri-list format: file:///path or path\n
+	log.Printf("uriToPath: input=%q", u)
-	if len(u) >= 7 && u[:7] == "file://" {
+
-		u = u[7:]
+	// text/uri-list format: file:///path
+	if strings.HasPrefix(u, "file://") {
+		// Use url.Parse to properly handle URL encoding
+		parsed, err := url.Parse(u)
+		if err != nil {
+			log.Printf("uriToPath: url.Parse error: %v", err)
+			// Fallback: just strip file://
+			u = strings.TrimPrefix(u, "file://")
+			// Handle localhost
+			u = strings.TrimPrefix(u, "localhost")
+			return u
+		}
+		path := parsed.Path
+		log.Printf("uriToPath: parsed path=%q", path)
+		return path
 	}
+
+	// Not a file:// URI, return as-is
 	return u
 }