view.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Copyright (C) 2018 Andy Stewart
#
# Author:     Andy Stewart <lazycat.manatee@gmail.com>
# Maintainer: Andy Stewart <lazycat.manatee@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import platform

from core.utils import current_desktop, eval_in_emacs, focus_emacs_buffer, get_emacs_func_cache_result, get_emacs_var
from PyQt6.QtCore import QEvent, QPoint, Qt
from PyQt6.QtGui import QBrush, QPainter, QWindow
from PyQt6.QtWidgets import QFrame, QGraphicsView, QVBoxLayout, QWidget

if current_desktop in ["sway", "Hyprland"] and get_emacs_func_cache_result("eaf-emacs-running-in-wayland-native", []):
    global reinput

    import subprocess

    build_dir = get_emacs_var("eaf-build-dir")
    reinput_file = build_dir + "reinput/reinput"
    pid = get_emacs_func_cache_result("emacs-pid", [])
    reinput = subprocess.Popen(f"{reinput_file} {pid}", stdin=subprocess.PIPE, shell=True)

def focus():
    reinput.stdin.write("1\n".encode("utf-8"))
    reinput.stdin.flush()

def lose_focus():
    reinput.stdin.write("0\n".encode("utf-8"))
    reinput.stdin.flush()


class View(QWidget):

    def __init__(self, buffer, view_info):

        super(View, self).__init__()

        self.buffer = buffer

        # Init widget attributes.
        if get_emacs_func_cache_result("eaf-emacs-running-in-wayland-native", []):
            self.setWindowFlags(Qt.WindowType.FramelessWindowHint | Qt.WindowType.WindowStaysOnTopHint | Qt.WindowType.WindowOverridesSystemGestures | Qt.WindowType.BypassWindowManagerHint)
        elif get_emacs_func_cache_result("eaf-emacs-not-use-reparent-technology", []):
            self.setWindowFlags(Qt.WindowType.FramelessWindowHint | Qt.WindowType.WindowStaysOnTopHint | Qt.WindowType.NoDropShadowWindowHint)
        else:
            self.setWindowFlags(Qt.WindowType.FramelessWindowHint)

        self.is_member_of_focus_fix_wms = get_emacs_var("eaf-is-member-of-focus-fix-wms")

        self.setAttribute(Qt.WidgetAttribute.WA_X11DoNotAcceptFocus, True)
        self.setContentsMargins(0, 0, 0, 0)
        self.installEventFilter(self)

        # Init attributes.
        self.last_event_type = None
        self.view_info = view_info
        (self.buffer_id, self.emacs_xid, self.x, self.y, self.width, self.height) = view_info.split(":")
        self.x: int = int(self.x)
        self.y: int = int(self.y)
        self.width: int = int(self.width)
        self.height: int = int(self.height)

        # Build QGraphicsView.
        self.layout: QVBoxLayout = QVBoxLayout(self)
        self.layout.setSpacing(0)
        self.layout.setContentsMargins(0, 0, 0, 0)
        self.graphics_view = QGraphicsView(buffer, self)

        # Remove border from QGraphicsView.
        self.graphics_view.setHorizontalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)
        self.graphics_view.setVerticalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)
        self.graphics_view.setRenderHints(QPainter.RenderHint.Antialiasing | QPainter.RenderHint.SmoothPixmapTransform | QPainter.RenderHint.TextAntialiasing)
        self.graphics_view.setFrameStyle(QFrame.Shape.NoFrame)

        # Fill background color.
        self.graphics_view.setBackgroundBrush(QBrush(buffer.background_color))

        # Add graphics view.
        self.layout.addWidget(self.graphics_view)

        # NOTE: show function must start before resize to trigger *first* resizeEvent after show.
        self.show()

        # Resize after show to trigger fit view operation.
        self.resize(self.width, self.height)

        self.buffer.aspect_ratio_change.connect(self.adjust_aspect_ratio)

        self.locate()

    def resizeEvent(self, event):
        # Fit content to view rect just when buffer fit_to_view option is enable.
        if self.buffer.fit_to_view:
            if event.oldSize().isValid():
                self.graphics_view.fitInView(self.graphics_view.scene().sceneRect(), Qt.AspectRatioMode.KeepAspectRatio)
                QWidget.resizeEvent(self, event)

    def adjust_aspect_ratio(self):
        widget_width = self.width
        widget_height = self.height

        if self.buffer.aspect_ratio == 0:
            self.buffer.buffer_widget.resize(self.width, self.height)

            self.layout.setContentsMargins(0, 0, 0, 0)
        else:
            view_height = widget_height * (1 - 2 * self.buffer.vertical_padding_ratio)
            view_width = view_height * self.buffer.aspect_ratio
            horizontal_padding = (widget_width - view_width) / 2
            vertical_padding = self.buffer.vertical_padding_ratio * widget_height

            self.buffer.buffer_widget.resize(int(view_width), int(view_height))

            self.layout.setContentsMargins(int(horizontal_padding), int(vertical_padding), int(horizontal_padding), int(vertical_padding))

    def is_switch_from_other_application(self, event):
        # When switch to Emacs from other application, such as Alt + Tab.
        #
        # Event match one of below rules:
        return (
            # Current event is QEvent.Type.ShortcutOverride
            (event.type() in [QEvent.Type.ShortcutOverride]) or

            # Current event is QEvent.Type.Enter.
            ((not self.is_member_of_focus_fix_wms) and
             (self.last_event_type not in [QEvent.Type.Resize, QEvent.Type.WinIdChange, QEvent.Type.Leave, QEvent.Type.UpdateRequest]) and
             (event.type() in [QEvent.Type.Enter])) or

            # Current event is QEvent.Type.KeyRelease and last event is QEvent.Type.UpdateRequest.
            ((not self.is_member_of_focus_fix_wms) and
             (self.last_event_type is QEvent.Type.UpdateRequest) and
             (event.type() is QEvent.Type.KeyRelease)))

    def eventFilter(self, obj, event):
        # ENABLE BELOW CODE FOR DEBUG.
        #
        # import time
        # current_time = time.time()
        # print(f"{current_time:.6f}" + " " + event.type().name)

        # Focus emacs window when event type match below event list.
        # Make sure EAF window always response user key event after switch from other application, such as Alt + Tab.
        if current_desktop in ["sway", "Hyprland"] and get_emacs_func_cache_result("eaf-emacs-running-in-wayland-native", []):
            if event.type() == QEvent.Type.WindowActivate:
                focus()
            elif event.type() == QEvent.Type.WindowDeactivate:
                lose_focus()

        if self.is_switch_from_other_application(event):
            eval_in_emacs('eaf-activate-emacs-window', [self.buffer_id])

        # Focus emacs buffer when user click view.
        focus_event_types = [QEvent.Type.MouseButtonPress, QEvent.Type.MouseButtonRelease, QEvent.Type.MouseButtonDblClick]
        if platform.system() != "Darwin":
            focus_event_types += [QEvent.Type.Wheel]

        self.last_event_type = event.type()

        if event.type() in focus_event_types:
            focus_emacs_buffer(self.buffer_id)
            # Stop mouse event.
            return True

        return False

    def showEvent(self, event):
        # NOTE: we must reparent after widget show, otherwise reparent operation maybe failed.
        self.reparent()

        if platform.system() in ["Windows", "Darwin"]:
            eval_in_emacs('eaf-activate-emacs-window', [])

        # Make graphics view at left-top corner after show.
        self.graphics_view.verticalScrollBar().setValue(0)
        self.graphics_view.horizontalScrollBar().setValue(0)

    def reparent(self):
        # print("Reparent: ", self.buffer.url)
        qwindow = self.windowHandle()

        if not get_emacs_func_cache_result("eaf-emacs-not-use-reparent-technology", []):
            qwindow.setParent(QWindow.fromWinId(int(self.emacs_xid)))    # type: ignore

        qwindow.setPosition(QPoint(self.x, self.y))

    def try_show_top_view(self):
        if get_emacs_func_cache_result("eaf-emacs-not-use-reparent-technology", []):
            self.setWindowFlag(Qt.WindowType.WindowStaysOnTopHint, True)
            self.show()

    def try_hide_top_view(self):
        if get_emacs_func_cache_result("eaf-emacs-not-use-reparent-technology", []):
            self.setWindowFlag(Qt.WindowType.WindowStaysOnTopHint, False)
            self.hide()

    def destroy_view(self):
        # print("Destroy: ", self.buffer.url)
        self.destroy()

    def screen_shot(self):
        return self.grab()

    def locate(self):
        if not get_emacs_func_cache_result("eaf-emacs-running-in-wayland-native", []):
            return

        title = f"eaf.py-{self.x}-{self.y}"
        if current_desktop == "Hyprland":
            import subprocess

            subprocess.Popen(f"hyprctl --batch 'keyword windowrule float,title:^{title}$;"
                             f"keyword windowrule move {self.x} {self.y},title:^{title}$'", shell=True)
            self.setWindowTitle(title)
        elif current_desktop == "sway" and get_emacs_func_cache_result("eaf-emacs-not-use-reparent-technology", []):
            import subprocess

            subprocess.Popen(f"swaymsg 'for_window [title={title}] floating enable;"
                             f"for_window [title={title}] move position {self.x} {self.y}'", shell=True)
            self.setWindowTitle(title)