// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ASH_TEST_PIXEL_ASH_PIXEL_DIFFER_H_
#define ASH_TEST_PIXEL_ASH_PIXEL_DIFFER_H_
#include <iterator>
#include <optional>
#include "ash/shell.h"
#include "ash/test/pixel/ash_pixel_diff_util.h"
#include "base/check_op.h"
#include "base/ranges/algorithm.h"
#include "ui/base/test/skia_gold_matching_algorithm.h"
#include "ui/display/screen.h"
#include "ui/display/test/display_manager_test_api.h"
#include "ui/views/test/view_skia_gold_pixel_diff.h"
namespace ash {
// A helper class that provides utility functions for performing pixel diff
// tests via the Skia Gold.
class AshPixelDiffer {
public:
// `screenshot_prefix` is the prefix of the screenshot names; `corpus`
// specifies the result group that will be used to store screenshots in Skia
// Gold. Read the comment of `SKiaGoldPixelDiff::GetSession()` for more
// details.
explicit AshPixelDiffer(const std::string& screenshot_prefix,
const std::optional<std::string>& corpus = {});
AshPixelDiffer(const AshPixelDiffer&) = delete;
AshPixelDiffer& operator=(const AshPixelDiffer&) = delete;
~AshPixelDiffer();
// Takes a full screenshot of `root_window` then compares it with the
// benchmark image specified by the function parameters. Only the pixels
// within the screen bounds of `ui_components` affect the comparison result.
// The pixels outside of `ui_components` are blacked out. Returns the
// comparison result. The function caller has the duty to choose suitable
// `ui_components` in their tests to avoid unnecessary pixel comparisons.
// Otherwise, pixel tests could be fragile to the changes in production code.
//
// Checks that `root_window` is not null and is actually a root window.
//
// `revision_number` indicates the benchmark image version. `revision_number`
// and `screenshot_name` collectively specify the benchmark image to compare
// with. The initial `revision_number` of a new benchmark image should be "0".
// If there is any code change that updates the benchmark, `revision_number`
// should increase by 1.
//
// `ui_components` is a variadic argument list, consisting of view pointers,
// widget pointers or window pointers. `ui_components` can have the pointers
// of different categories.
//
// Note that there exist two convenience functions,
// `CompareUiComponentsOnPrimaryScreen()` and
// `CompareUiComponentsOnSecondaryScreen()`, for comparing the UI components
// against the primary or secondary display's root window, respectively. They
// can be used in a similar way to the example below, with the difference of
// not having to provide a particular `root_window`.
//
// Example usages (of `CompareUiComponentsOnRootWindow()`):
//
// aura::Window* root_window = ...;
// views::View* view_ptr = ...;
// views::Widget* widget_ptr = ...;
// aura::Window* window_ptr = ...;
//
// CompareUiComponentsOnRootWindow(root_window,
// "foo_name1",
// /*revision_number=*/0,
// view_ptr);
//
// CompareUiComponentsOnRootWindow(root_window,
// "foo_name2",
// /*revision_number=*/0,
// view_ptr,
// widget_ptr,
// window_ptr);
template <class... UiComponentTypes>
bool CompareUiComponentsOnRootWindow(aura::Window* const root_window,
const std::string& screenshot_name,
size_t revision_number,
UiComponentTypes... ui_components) {
CHECK(root_window && root_window->IsRootWindow());
CHECK_GT(sizeof...(ui_components), 0u);
std::vector<gfx::Rect> rects_in_screen;
PopulateUiComponentScreenBounds(&rects_in_screen, ui_components...);
// Adjust the UI component bounds to be relative to the origin of the
// specified root window.
std::vector<gfx::Rect> adjusted_rects_in_screen;
const gfx::Rect root_window_bounds = root_window->GetBoundsInScreen();
base::ranges::transform(
rects_in_screen, std::back_inserter(adjusted_rects_in_screen),
[&root_window_bounds](const gfx::Rect& rect) {
gfx::Rect adjusted_rect(rect);
adjusted_rect.Offset(-root_window_bounds.OffsetFromOrigin());
return adjusted_rect;
});
return CompareScreenshotForRootWindowInRects(root_window, screenshot_name,
revision_number,
adjusted_rects_in_screen);
}
// Like `CompareUiComponentsOnRootWindow()` but forces the screenshot to be of
// the primary display's root window.
//
// TODO(b/286916355): Rename this function.
template <class... UiComponentTypes>
bool CompareUiComponentsOnPrimaryScreen(const std::string& screenshot_name,
size_t revision_number,
UiComponentTypes... ui_components) {
return CompareUiComponentsOnRootWindow(Shell::GetPrimaryRootWindow(),
screenshot_name, revision_number,
ui_components...);
}
// Like `CompareUiComponentsOnRootWindow()` but forces the screenshot to be of
// the secondary display's root window. There should be exactly two displays
// present when using this function; if there are more than two displays then
// consider using `CompareUiComponentsOnRootWindow()` instead to ensure the
// proper root window is used for the comparison.
//
// TODO(b/286916355): Rename this function.
template <class... UiComponentTypes>
bool CompareUiComponentsOnSecondaryScreen(const std::string& screenshot_name,
size_t revision_number,
UiComponentTypes... ui_components) {
CHECK_EQ(Shell::GetAllRootWindows().size(), 2u);
const display::Display& display =
display::test::DisplayManagerTestApi(Shell::Get()->display_manager())
.GetSecondaryDisplay();
return CompareUiComponentsOnRootWindow(
Shell::GetRootWindowForDisplayId(display.id()), screenshot_name,
revision_number, ui_components...);
}
private:
// Compares a screenshot of `root_window` with the specified benchmark image.
// Only the pixels in `rects_in_screen` affect the comparison result.
bool CompareScreenshotForRootWindowInRects(
aura::Window* const root_window,
const std::string& screenshot_name,
size_t revision_number,
const std::vector<gfx::Rect>& rects_in_screen);
ui::test::PositiveIfOnlyImageAlgorithm positive_if_only_algorithm_;
// Used to take screenshots and upload images to the Skia Gold server to
// perform pixel comparison.
views::ViewSkiaGoldPixelDiff pixel_diff_;
};
} // namespace ash
#endif // ASH_TEST_PIXEL_ASH_PIXEL_DIFFER_H_
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