ladybird/Services/WindowServer/Button.cpp
Tom a698a58d3c WindowServer: Fix flickering
Rather than blitting and rendering each window every time, only
render what actually changed. And while doing so, only render
the portions that are visible on the screen. This avoids flickering
because flipping framebuffers isn't always perfectly in sync with
the code, so it's possible that the flip happens slightly delayed
and we can briefly see the next iteration having partially completed.

Also, avoid touching the mouse cursor unless it is in an area that
needs updating. This reduces flickering unless it is over an area
that is updated often. And because we no longer render the entire
screen, we'll save the contents below the cursor so that we can
hide it before touching that area.

Fixes #2981
2020-08-18 12:12:27 +02:00

116 lines
4.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <LibGfx/CharacterBitmap.h>
#include <LibGfx/Painter.h>
#include <LibGfx/StylePainter.h>
#include <WindowServer/Button.h>
#include <WindowServer/Event.h>
#include <WindowServer/WindowManager.h>
namespace WindowServer {
Button::Button(WindowFrame& frame, Function<void(Button&)>&& on_click_handler)
: on_click(move(on_click_handler))
, m_frame(frame)
{
}
Button::~Button()
{
}
void Button::paint(Gfx::Painter& painter)
{
auto palette = WindowManager::the().palette();
Gfx::PainterStateSaver saver(painter);
painter.translate(relative_rect().location());
Gfx::StylePainter::paint_button(painter, rect(), palette, Gfx::ButtonStyle::Normal, m_pressed, m_hovered);
if (m_icon) {
auto icon_location = rect().center().translated(-(m_icon->width() / 2), -(m_icon->height() / 2));
if (m_pressed)
painter.translate(1, 1);
painter.blit(icon_location, *m_icon, m_icon->rect());
}
}
void Button::on_mouse_event(const MouseEvent& event)
{
auto& wm = WindowManager::the();
if (event.type() == Event::MouseDown && event.button() == MouseButton::Left) {
m_pressed = true;
wm.set_cursor_tracking_button(this);
m_frame.invalidate(m_relative_rect);
return;
}
if (event.type() == Event::MouseUp && event.button() == MouseButton::Left) {
if (wm.cursor_tracking_button() != this)
return;
wm.set_cursor_tracking_button(nullptr);
bool old_pressed = m_pressed;
m_pressed = false;
if (rect().contains(event.position())) {
if (on_click)
on_click(*this);
}
if (old_pressed != m_pressed) {
// Would like to compute:
// m_hovered = rect_after_action().contains(event.position());
// However, we don't know that rect yet. We can make an educated
// guess which also looks okay even when wrong:
m_hovered = false;
m_frame.invalidate(m_relative_rect);
}
return;
}
if (event.type() == Event::MouseMove) {
bool old_hovered = m_hovered;
m_hovered = rect().contains(event.position());
wm.set_hovered_button(m_hovered ? this : nullptr);
if (old_hovered != m_hovered)
m_frame.invalidate(m_relative_rect);
}
if (event.type() == Event::MouseMove && event.buttons() & (unsigned)MouseButton::Left) {
if (wm.cursor_tracking_button() != this)
return;
bool old_pressed = m_pressed;
m_pressed = m_hovered;
if (old_pressed != m_pressed)
m_frame.invalidate(m_relative_rect);
}
}
Gfx::IntRect Button::screen_rect() const
{
return m_relative_rect.translated(m_frame.rect().location());
}
}