/* * Copyright (c) 2022, Tim Flynn * * SPDX-License-Identifier: BSD-2-Clause */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include namespace Web::WebDriver { // https://w3c.github.io/webdriver/#dfn-encoding-a-canvas-as-base64 static Response encode_canvas_element(HTML::HTMLCanvasElement& canvas) { // FIXME: 1. If the canvas element’s bitmap’s origin-clean flag is set to false, return error with error code unable to capture screen. // 2. If the canvas element’s bitmap has no pixels (i.e. either its horizontal dimension or vertical dimension is zero) then return error with error code unable to capture screen. if (canvas.bitmap()->width() == 0 || canvas.bitmap()->height() == 0) return Error::from_code(ErrorCode::UnableToCaptureScreen, "Captured screenshot is empty"sv); // 3. Let file be a serialization of the canvas element’s bitmap as a file, using "image/png" as an argument. // 4. Let data url be a data: URL representing file. [RFC2397] auto data_url = canvas.to_data_url("image/png"sv, {}); // 5. Let index be the index of "," in data url. auto index = data_url.find_byte_offset(','); VERIFY(index.has_value()); // 6. Let encoded string be a substring of data url using (index + 1) as the start argument. auto encoded_string = MUST(data_url.substring_from_byte_offset(*index + 1)); // 7. Return success with data encoded string. return JsonValue { move(encoded_string) }; } // Common animation callback steps between: // https://w3c.github.io/webdriver/#take-screenshot // https://w3c.github.io/webdriver/#take-element-screenshot Response capture_element_screenshot(Painter const& painter, Page& page, DOM::Element& element, Gfx::IntRect& rect) { Optional encoded_string_or_error; // https://w3c.github.io/webdriver/#dfn-draw-a-bounding-box-from-the-framebuffer auto draw_bounding_box_from_the_framebuffer = [&]() -> ErrorOr, WebDriver::Error> { // 1. If either the initial viewport's width or height is 0 CSS pixels, return error with error code unable to capture screen. auto viewport_rect = page.top_level_traversable()->viewport_rect(); if (viewport_rect.is_empty()) return Error::from_code(ErrorCode::UnableToCaptureScreen, "Viewport is empty"sv); auto viewport_device_rect = page.enclosing_device_rect(viewport_rect).to_type(); // 2. Let paint width be the initial viewport's width – min(rectangle x coordinate, rectangle x coordinate + rectangle width dimension). auto paint_width = viewport_device_rect.width() - min(rect.x(), rect.x() + rect.width()); // 3. Let paint height be the initial viewport's height – min(rectangle y coordinate, rectangle y coordinate + rectangle height dimension). auto paint_height = viewport_device_rect.height() - min(rect.y(), rect.y() + rect.height()); // 4. Let canvas be a new canvas element, and set its width and height to paint width and paint height, respectively. auto canvas_element = DOM::create_element(element.document(), HTML::TagNames::canvas, Namespace::HTML).release_value_but_fixme_should_propagate_errors(); auto& canvas = verify_cast(*canvas_element); // FIXME: Handle DevicePixelRatio in HiDPI mode. MUST(canvas.set_width(paint_width)); MUST(canvas.set_height(paint_height)); // FIXME: 5. Let context, a canvas context mode, be the result of invoking the 2D context creation algorithm given canvas as the target. if (!canvas.create_bitmap(paint_width, paint_height)) return Error::from_code(ErrorCode::UnableToCaptureScreen, "Unable to create a screenshot bitmap"sv); // 6. Complete implementation specific steps equivalent to drawing the region of the framebuffer specified by the following coordinates onto context: // - X coordinate: rectangle x coordinate // - Y coordinate: rectangle y coordinate // - Width: paint width // - Height: paint height Gfx::IntRect paint_rect { rect.x(), rect.y(), paint_width, paint_height }; painter(paint_rect, *canvas.bitmap()); // 7. Return success with canvas. return canvas; }; (void)element.document().window()->animation_frame_callback_driver().add([&](auto) { auto canvas_or_error = draw_bounding_box_from_the_framebuffer(); if (canvas_or_error.is_error()) { encoded_string_or_error = canvas_or_error.release_error(); return; } encoded_string_or_error = encode_canvas_element(canvas_or_error.release_value()); }); Platform::EventLoopPlugin::the().spin_until([&]() { return encoded_string_or_error.has_value(); }); return encoded_string_or_error.release_value(); } }