Piggy: add capture QR code

ThomasFarstrike · ThomasFarstrike · commit c0ff7fae3271 · 2025-05-31T23:21:05.000+02:00
Also cleanup top layer when opening a new screen.
diff --git a/internal_filesystem/apps/com.lightningpiggy.displaywallet/assets/captureqr.py b/internal_filesystem/apps/com.lightningpiggy.displaywallet/assets/captureqr.py
@@ -0,0 +1,286 @@
+# This code grabs images from the camera in RGB565 format (2 bytes per pixel)
+# and sends that to the QR decoder if QR decoding is enabled.
+# The QR decoder then converts the RGB565 to grayscale, as that's what quirc operates on.
+# It would be slightly more efficient to capture the images from the camera in L8/grayscale format,
+# or in YUV format and discarding the U and V planes, but then the image will be gray (not great UX)
+# and the performance impact of converting RGB565 to grayscale is probably minimal anyway.
+
+import lvgl as lv
+import time
+
+import mpos.apps
+import mpos.clipboard
+import mpos.ui
+
+# screens:
+main_screen = None
+
+keepliveqrdecoding = False
+width = 240
+height = 240
+
+# Variable to hold the current memoryview to prevent garbage collection
+current_cam_buffer = None
+image_dsc = None
+image = None
+qr_label = None
+
+use_webcam = False
+qr_button = None
+snap_button = None
+
+status_label = None
+status_label_cont = None
+status_label_text = "No camera found."
+status_label_text_searching = "Searching QR codes..."
+status_label_text_found = "Decoding QR..."
+
+def print_qr_buffer(buffer):
+    try:
+        # Try to decode buffer as a UTF-8 string
+        result = buffer.decode('utf-8')
+        # Check if the string is printable (ASCII printable characters)
+        if all(32 <= ord(c) <= 126 for c in result):
+            return result
+    except Exception as e:
+        pass
+    # If not a valid string or not printable, convert to hex
+    hex_str = ' '.join([f'{b:02x}' for b in buffer])
+    return hex_str.lower()
+
+# Byte-Order-Mark is added sometimes
+def remove_bom(buffer):
+    bom = b'\xEF\xBB\xBF'
+    if buffer.startswith(bom):
+        return buffer[3:]
+    return buffer
+
+def qrdecode_one():
+    global status_label, status_label_text
+    try:
+        import qrdecode
+        result = qrdecode.qrdecode_rgb565(current_cam_buffer, width, height)
+        result = bytearray("INSERT_QR_HERE", "utf-8")
+        if not result:
+            status_label.set_text(status_label_text_searching)
+        else:
+            result = remove_bom(result)
+            result = print_qr_buffer(result)
+            print(f"QR decoding found: {result}")
+            status_label.set_text(result)
+            stop_qr_decoding()
+            mpos.clipboard.add(f"Result: {result}")
+            mpos.ui.back_screen()
+    except ValueError as e:
+        print("QR ValueError: ", e)
+        status_label.set_text(status_label_text_searching)
+    except TypeError as e:
+        print("QR TypeError: ", e)
+        status_label.set_text(status_label_text_found)
+    except Exception as e:
+        print("QR got other error: ", e)
+
+
+def close_button_click(e):
+    print("Close button clicked")
+    mpos.ui.back_screen()
+
+
+def snap_button_click(e):
+    print("Picture taken!")
+    import os
+    try:
+        os.mkdir("data")
+    except OSError:
+        pass
+    try:
+        os.mkdir("data/com.example.camtest")
+    except OSError:
+        pass
+    if current_cam_buffer is not None:
+        filename="data/com.example.camtest/capture.raw"
+        try:
+            with open(filename, 'wb') as f:
+                f.write(current_cam_buffer)
+            print(f"Successfully wrote current_cam_buffer to {filename}")
+        except OSError as e:
+            print(f"Error writing to file: {e}")
+
+
+def start_qr_decoding():
+    global qr_label, keepliveqrdecoding, status_label_cont, status_label
+    print("Activating live QR decoding...")
+    keepliveqrdecoding = True
+    qr_label.set_text(lv.SYMBOL.EYE_CLOSE)
+    status_label_cont.remove_flag(lv.obj.FLAG.HIDDEN)
+    status_label.set_text(status_label_text_searching)
+
+def stop_qr_decoding():
+    global qr_label, keepliveqrdecoding
+    print("Deactivating live QR decoding...")
+    keepliveqrdecoding = False
+    qr_label.set_text(lv.SYMBOL.EYE_OPEN)
+    status_label_text = status_label.get_text()
+    if status_label_text == status_label_text_searching or status_label_text == status_label_text_found: # if it found a QR code, then leave it
+        status_label_cont.add_flag(lv.obj.FLAG.HIDDEN)
+
+
+def qr_button_click(e):
+    global keepliveqrdecoding
+    if not keepliveqrdecoding:
+        start_qr_decoding()
+    else:
+        stop_qr_decoding()
+
+def try_capture(event):
+    #print("capturing camera frame")
+    global current_cam_buffer, image_dsc, image, use_webcam
+    try:
+        if use_webcam:
+            current_cam_buffer = webcam.capture_frame(cam, "rgb565")
+        elif cam.frame_available():
+            current_cam_buffer = cam.capture()
+        if current_cam_buffer and len(current_cam_buffer):
+            image_dsc.data = current_cam_buffer
+            #image.invalidate() # does not work so do this:
+            image.set_src(image_dsc)
+            if not use_webcam:
+                cam.free_buffer()  # Free the old buffer
+            if keepliveqrdecoding:
+                qrdecode_one()
+    except Exception as e:
+        print(f"Camera capture exception: {e}")
+
+
+def build_ui():
+    global image, image_dsc,qr_label, status_label, cam, use_webcam, qr_button, snap_button, status_label_cont, main_screen
+    main_screen = lv.obj()
+    main_screen.set_style_pad_all(0, 0)
+    main_screen.set_style_border_width(0, 0)
+    main_screen.set_size(lv.pct(100), lv.pct(100))
+    main_screen.set_scrollbar_mode(lv.SCROLLBAR_MODE.OFF)
+    close_button = lv.button(main_screen)
+    close_button.set_size(60,60)
+    close_button.align(lv.ALIGN.TOP_RIGHT, 0, 0)
+    close_label = lv.label(close_button)
+    close_label.set_text(lv.SYMBOL.CLOSE)
+    close_label.center()
+    close_button.add_event_cb(close_button_click,lv.EVENT.CLICKED,None)
+    snap_button = lv.button(main_screen)
+    snap_button.set_size(60, 60)
+    snap_button.align(lv.ALIGN.RIGHT_MID, 0, 0)
+    snap_button.add_flag(lv.obj.FLAG.HIDDEN)
+    snap_label = lv.label(snap_button)
+    snap_label.set_text(lv.SYMBOL.OK)
+    snap_label.center()
+    snap_button.add_event_cb(snap_button_click,lv.EVENT.CLICKED,None)
+    qr_button = lv.button(main_screen)
+    qr_button.set_size(60, 60)
+    qr_button.add_flag(lv.obj.FLAG.HIDDEN)
+    qr_button.align(lv.ALIGN.BOTTOM_RIGHT, 0, 0)
+    qr_label = lv.label(qr_button)
+    qr_label.set_text(lv.SYMBOL.EYE_OPEN)
+    qr_label.center()
+    qr_button.add_event_cb(qr_button_click,lv.EVENT.CLICKED,None)
+    # Initialize LVGL image widget
+    image = lv.image(main_screen)
+    image.align(lv.ALIGN.LEFT_MID, 0, 0)
+    # Create image descriptor once
+    image_dsc = lv.image_dsc_t({
+        "header": {
+            "magic": lv.IMAGE_HEADER_MAGIC,
+            "w": width,
+            "h": height,
+            "stride": width * 2,
+            "cf": lv.COLOR_FORMAT.RGB565
+            #"cf": lv.COLOR_FORMAT.L8
+        },
+        'data_size': width * height * 2,
+        'data': None # Will be updated per frame
+    })
+    image.set_src(image_dsc)
+    status_label_cont = lv.obj(main_screen)
+    status_label_cont.set_size(lv.pct(66),lv.pct(60))
+    status_label_cont.align(lv.ALIGN.LEFT_MID, lv.pct(5), 0)
+    status_label_cont.set_style_bg_color(lv.color_white(), 0)
+    status_label_cont.set_style_bg_opa(66, 0)
+    status_label_cont.set_style_border_width(0, 0)
+    status_label = lv.label(status_label_cont)
+    status_label.set_text("No camera found.")
+    status_label.set_long_mode(lv.label.LONG.WRAP)
+    status_label.set_style_text_color(lv.color_white(), 0)
+    status_label.set_width(lv.pct(100))
+    status_label.center()
+    mpos.ui.load_screen(main_screen)
+
+
+def init_cam():
+    try:
+        from camera import Camera, GrabMode, PixelFormat, FrameSize, GainCeiling
+        cam = Camera(
+            data_pins=[12,13,15,11,14,10,7,2],
+            vsync_pin=6,
+            href_pin=4,
+            sda_pin=21,
+            scl_pin=16,
+            pclk_pin=9,
+            xclk_pin=8,
+            xclk_freq=20000000,
+            powerdown_pin=-1,
+            reset_pin=-1,
+            pixel_format=PixelFormat.RGB565,
+            #pixel_format=PixelFormat.GRAYSCALE,
+            frame_size=FrameSize.R240X240,
+            grab_mode=GrabMode.LATEST 
+        )
+        #cam.init() automatically done when creating the Camera()
+        #cam.reconfigure(frame_size=FrameSize.HVGA)
+        #frame_size=FrameSize.HVGA, # 480x320
+        #frame_size=FrameSize.QVGA, # 320x240
+        #frame_size=FrameSize.QQVGA # 160x120
+        cam.set_vflip(True)
+        return cam
+    except Exception as e:
+        print(f"init_cam exception: {e}")
+        return None
+
+
+
+def check_running(timer):
+    if lv.screen_active() != main_screen:
+        print("camtest.py backgrounded, cleaning up...")
+        check_running_timer.delete()
+        if capture_timer:
+            capture_timer.delete()
+        if use_webcam:
+            webcam.deinit(cam)
+        elif cam:
+            cam.deinit()
+        print("camtest.py cleanup done.")
+
+
+
+build_ui()
+
+cam = init_cam()
+if cam:
+    image.set_rotation(900) # internal camera is rotated 90 degrees
+else:
+    print("camtest.py: no internal camera found, trying webcam on /dev/video0")
+    try:
+        import webcam
+        cam = webcam.init("/dev/video0")
+        use_webcam = True
+    except Exception as e:
+        print(f"camtest.py: webcam exception: {e}")
+
+if cam:
+    print("Camera initialized, continuing...")
+    check_running_timer = lv.timer_create(check_running, 500, None)
+    qr_button.remove_flag(lv.obj.FLAG.HIDDEN)
+    #snap_button.remove_flag(lv.obj.FLAG.HIDDEN)
+    status_label_cont.add_flag(lv.obj.FLAG.HIDDEN)
+    capture_timer = lv.timer_create(try_capture, 100, None)
+    start_qr_decoding()
+else:
+   print("No camera found, stopping camtest.py")
diff --git a/internal_filesystem/lib/mpos/ui.py b/internal_filesystem/lib/mpos/ui.py
@@ -480,6 +480,7 @@ def load_screen(screen):
         screen_stack.append(screen)
     else:
         print("Warning: not adding new screen to screen_stack because it's already there, just bringing to foreground.")
+    close_top_layer_msgboxes() # otherwise they remain
     lv.screen_load(screen)
 
 def back_screen():
