lintunes/tests/test_round80.py

"""Round 80: scrollbars lose their arrow buttons, and the thumb is a button.

- No arrows: the trough runs the bar's full length and the arrow rects are
  empty, so nothing paints or hit-tests there.
- The thumb gets the buttons' corner radius and emboss, with rims as tall in
  pixels as a button's, however long the thumb.
- The bar's thickness comes from the UI scale through the style, not QSS
  (any QSS rule on a scrollbar part makes Qt draw the arrows itself).
"""
from PyQt6.QtCore import Qt
from PyQt6.QtGui import QColor
from PyQt6.QtWidgets import QPushButton, QScrollBar, QStyle, QStyleOptionSlider

from lintunes import theme
from lintunes.gui.track_table import ClickToJumpScrollStyle

SC = QStyle.SubControl


def _option(bar):
    opt = QStyleOptionSlider()
    bar.initStyleOption(opt)
    return opt


def _bar(qapp, orientation=Qt.Orientation.Vertical):
    bar = QScrollBar(orientation)
    bar.setStyle(ClickToJumpScrollStyle())
    bar.setRange(0, 900)
    bar.setPageStep(100)
    bar.resize(14, 400) if orientation == Qt.Orientation.Vertical \
        else bar.resize(400, 14)
    return bar


def test_no_arrow_buttons(qapp):
    bar = _bar(qapp)
    style, opt = bar.style(), _option(bar)
    cc = QStyle.ComplexControl.CC_ScrollBar
    assert style.subControlRect(cc, opt, SC.SC_ScrollBarAddLine, bar).isEmpty()
    assert style.subControlRect(cc, opt, SC.SC_ScrollBarSubLine, bar).isEmpty()
    assert style.subControlRect(cc, opt, SC.SC_ScrollBarGroove, bar) == opt.rect


def test_thumb_spans_the_full_trough(qapp):
    for orientation in (Qt.Orientation.Vertical, Qt.Orientation.Horizontal):
        bar = _bar(qapp, orientation)
        style, cc = bar.style(), QStyle.ComplexControl.CC_ScrollBar
        bar.setValue(0)
        top = style.subControlRect(cc, _option(bar), SC.SC_ScrollBarSlider, bar)
        bar.setValue(900)
        end = style.subControlRect(cc, _option(bar), SC.SC_ScrollBarSlider, bar)
        if orientation == Qt.Orientation.Vertical:
            assert top.top() == 0 and end.bottom() == 399
            assert top.height() == 40           # 100 / (900 + 100) of 400
        else:
            assert top.left() == 0 and end.right() == 399


def test_tiny_page_keeps_a_grabbable_thumb(qapp):
    bar = _bar(qapp)
    bar.setRange(0, 100000)
    rect = bar.style().subControlRect(QStyle.ComplexControl.CC_ScrollBar,
                                      _option(bar), SC.SC_ScrollBarSlider, bar)
    assert rect.height() == ClickToJumpScrollStyle.extent * 2


def test_thickness_follows_ui_scale(qapp):
    class Prefs(dict):
        def get(self, key, default=None):
            return "large" if key == "ui_scale" else default
    before = ClickToJumpScrollStyle.extent
    try:
        theme.apply_theme(qapp, Prefs())
        assert ClickToJumpScrollStyle.extent == theme.UI_SCALES["large"]["scrollbar"]
        assert "QScrollBar" not in qapp.styleSheet()
    finally:
        ClickToJumpScrollStyle.extent = before


def test_thumb_is_shaded_like_a_real_button(qapp):
    qapp.setStyleSheet(theme.button_emboss_qss(QColor("#d0d0d0")))
    try:
        button = QPushButton("OK")
        assert abs(theme.button_height_px(button.fontMetrics())
                   - button.sizeHint().height()) <= 2
    finally:
        qapp.setStyleSheet("")


def test_thumb_paints(qapp):
    bar = _bar(qapp)
    bar.setValue(450)
    image = bar.grab().toImage()
    thumb = bar.style().subControlRect(QStyle.ComplexControl.CC_ScrollBar,
                                       _option(bar), SC.SC_ScrollBarSlider, bar)
    trough = image.pixelColor(7, 5)
    middle = image.pixelColor(7, thumb.center().y())
    assert middle != trough


# --------------------------------------------------------------------------
# no album art: a debossed panel on the window, not a box in the list
# --------------------------------------------------------------------------

def _sidebar(qapp, tmp_path):
    from lintunes.gui.main_window import MainWindow
    from lintunes.library_manager import LibraryManager
    from lintunes.models.library import Library
    from lintunes.models.track import Track
    from lintunes.preferences import Preferences
    library = Library(tracks={1: Track(track_id=1, name="One")})
    window = MainWindow(LibraryManager(library, tmp_path), Preferences(tmp_path))
    window.resize(1000, 700)
    window.show()
    qapp.processEvents()
    return window, window.sidebar


def test_no_art_panel_sits_below_the_frame(qapp, tmp_path):
    from lintunes.gui.sidebar import NO_ART_GAP
    window, sidebar = _sidebar(qapp, tmp_path)
    art = sidebar.art
    assert not art.has_art()
    assert art.parentWidget() is sidebar
    assert art.y() >= sidebar.list_area.geometry().bottom()
    assert art.height() == art.width() + NO_ART_GAP
    image = art.grab().toImage()
    window_bg = art.palette().window().color()
    # the gap above is bare window; the panel's middle is the visualizer's
    # color, flat, not shaded gray over its whole height
    assert image.pixelColor(art.width() // 2, 1) == window_bg
    panel = art.palette().alternateBase().color()
    for y in (art.height() // 3, art.height() // 2, 2 * art.height() // 3):
        assert image.pixelColor(art.width() // 2, y) == panel
    window.close()


def test_tall_deboss_copies_a_short_panels_edges(qapp):
    """Shaded ``like`` a 62 px panel, a 400 px one matches it row for row
    along the top, and is flat in the middle."""
    from PyQt6.QtCore import QRectF
    from PyQt6.QtGui import QImage, QPainter
    color = QColor("#f2f2f2")

    def paint(height, **kw):
        image = QImage(100, height, QImage.Format.Format_ARGB32)
        image.fill(0)
        painter = QPainter(image)
        theme.paint_deboss(painter, QRectF(0.5, 0.5, 99, height - 1),
                           color, 8, **kw)
        painter.end()
        return image

    short, tall = paint(62), paint(400, like=62)
    for y in (3, 10, 20):
        assert abs(short.pixelColor(50, y).lightness()
                   - tall.pixelColor(50, y).lightness()) <= 1
    assert tall.pixelColor(50, 200) == color