fix: Screenshot capture with DISPLAY env and full screen

- Use full screen capture instead of active window (more reliable)
- Explicitly preserve and set DISPLAY environment variable
- Default to :0 if DISPLAY not set
- Better error logging with stderr output
- Use time.time() instead of date command for timestamp

Fixes screenshot failures when DISPLAY not inherited from parent process.
Changes from window-specific capture to full screen for better reliability.

Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Jean-Philippe Brule <jp@svrnty.io>

claude_vision_auto/screenshot.py

@@ -26,11 +26,14 @@ def find_screenshot_tool() -> Optional[str]:
 
 def take_screenshot() -> Optional[str]:
     """
-    Take screenshot of active terminal window
+    Take screenshot of full screen
 
     Returns:
         Path to screenshot file, or None if capture failed
     """
+    import os
+    import time
+
     tool = find_screenshot_tool()
 
     if not tool:
@@ -40,41 +43,49 @@ def take_screenshot() -> Optional[str]:
 
     # Create temporary file
     cache_dir = config.get_cache_dir()
-    screenshot_path = cache_dir / f"screenshot_{int(subprocess.check_output(['date', '+%s']).decode().strip())}.png"
+    screenshot_path = cache_dir / f"screenshot_{int(time.time())}.png"
+
+    # Preserve DISPLAY environment variable
+    env = os.environ.copy()
+    if 'DISPLAY' not in env:
+        env['DISPLAY'] = ':0'  # Default X display
 
     try:
         if tool == "scrot":
-            # Capture active window
+            # Capture full screen (more reliable than -u for active window)
-            subprocess.run(
+            result = subprocess.run(
-                ["scrot", "-u", str(screenshot_path)],
+                ["scrot", str(screenshot_path)],
                 check=True,
                 capture_output=True,
-                timeout=config.SCREENSHOT_TIMEOUT
+                timeout=config.SCREENSHOT_TIMEOUT,
+                env=env
             )
         elif tool == "gnome-screenshot":
-            # Capture active window
+            # Capture full screen
-            subprocess.run(
+            result = subprocess.run(
-                ["gnome-screenshot", "-w", "-f", str(screenshot_path)],
+                ["gnome-screenshot", "-f", str(screenshot_path)],
                 check=True,
                 capture_output=True,
-                timeout=config.SCREENSHOT_TIMEOUT
+                timeout=config.SCREENSHOT_TIMEOUT,
+                env=env
             )
         elif tool == "import":
             # ImageMagick - capture root window
-            subprocess.run(
+            result = subprocess.run(
                 ["import", "-window", "root", str(screenshot_path)],
                 check=True,
                 capture_output=True,
-                timeout=config.SCREENSHOT_TIMEOUT
+                timeout=config.SCREENSHOT_TIMEOUT,
+                env=env
             )
         elif tool == "maim":
-            # Capture active window
+            # Capture full screen
-            subprocess.run(
+            result = subprocess.run(
-                ["maim", "-i", "$(xdotool getactivewindow)", str(screenshot_path)],
+                ["maim", str(screenshot_path)],
-                shell=True,
                 check=True,
                 capture_output=True,
-                timeout=config.SCREENSHOT_TIMEOUT
+                timeout=config.SCREENSHOT_TIMEOUT,
+                env=env
             )
         else:
             return None
@@ -86,17 +97,19 @@ def take_screenshot() -> Optional[str]:
         else:
             return None
 
-    except subprocess.TimeoutExpired:
+    except subprocess.TimeoutExpired as e:
         if config.DEBUG:
             print(f"[DEBUG] Screenshot timeout with tool: {tool}")
         return None
     except subprocess.CalledProcessError as e:
         if config.DEBUG:
-            print(f"[DEBUG] Screenshot failed: {e}")
+            print(f"[DEBUG] Screenshot failed with {tool}: {e}")
+            if e.stderr:
+                print(f"[DEBUG] Error output: {e.stderr.decode('utf-8', errors='ignore')}")
         return None
     except Exception as e:
         if config.DEBUG:
-            print(f"[DEBUG] Unexpected error: {e}")
+            print(f"[DEBUG] Unexpected screenshot error: {type(e).__name__}: {e}")
         return None