Should I use QGraphicsView to display an image and some decorated text side by side? - qt

Question

I want to create a "details" view for books I have downloaded.
With the attached image as an example, imagine the red block to the left is the book's cover page, and metadata related to it is displayed to the right.
With the way I have it done right now:
from PySide6 import QtWidgets as qtw
from PySide6 import QtGui as qtg
from PySide6 import QtCore as qtc
class Details:
def __init__(self):
self.location = "/home/user/Desktop/Untitled.png"
self.title = "Some title"
self.subtitle = "Sub title"
self.id = 123124
def to_html(self):
return """
<p>
<b>Author =</b> author<br/>
<b>Published Date =</b> 2000-1-1<br/>
<b>Pages =</b> 500<br/>
</p>
"""
class DetailsWidget(qtw.QWidget):
_title_font = qtg.QFont()
_title_font.setBold(True)
_title_font.setPixelSize(24)
_subtitle_font = qtg.QFont()
_subtitle_font.setBold(True)
_subtitle_font.setPixelSize(19)
_id_font = qtg.QFont()
_id_font.setBold(True)
_id_font.setPixelSize(15)
_redacted_details_font = qtg.QFont()
_redacted_details_font.setPixelSize(12)
def __init__(self, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
self.setFixedSize(1000, 500)
self.setWindowFlag(qtc.Qt.WindowType.Dialog, True)
self.setLayout(qtw.QGridLayout())
self.layout().setContentsMargins(0, 0, 0, 0)
self._details: Details = Details()
self._thumbnail_image = qtg.QImage(self._details.location)
self._thumbnail_image = self._thumbnail_image.scaled(
500,
500,
qtc.Qt.AspectRatioMode.KeepAspectRatio,
qtc.Qt.TransformationMode.SmoothTransformation,
)
self._details_rect = qtc.QRect(
self._get_actual_geometry().left() + self._thumbnail_image.width() + 10,
self._get_actual_geometry().top(),
self._get_actual_geometry().width() - self._thumbnail_image.width() - 20,
self._get_actual_geometry().height(),
)
height = 0
self._title_rects = []
font_metrics_rect = qtg.QFontMetrics(self._title_font).boundingRect(
self._details_rect, qtc.Qt.TextFlag.TextWordWrap, self._details.title, 0
)
drawing_rect = qtc.QRect(self._details_rect)
self._title_rects.append(drawing_rect)
height += font_metrics_rect.height() + 10
drawing_rect = qtc.QRect(self._details_rect)
drawing_rect.moveTop(height)
self._title_rects.append(drawing_rect)
font_metrics_rect = qtg.QFontMetrics(self._title_font).boundingRect(
self._details_rect, qtc.Qt.TextFlag.TextWordWrap, self._details.subtitle, 0
)
drawing_rect = qtc.QRect(self._details_rect)
height += font_metrics_rect.height() - 3
drawing_rect.moveTop(height)
self._title_rects.append(drawing_rect)
font_metrics_rect = qtg.QFontMetrics(self._title_font).boundingRect(
self._details_rect,
qtc.Qt.TextFlag.TextWordWrap,
str(self._details.id),
0,
)
self._title_rects.append(drawing_rect)
height += font_metrics_rect.height() + 10
self._details_rect.moveTop(height)
self._redacted_details_text_document = qtg.QTextDocument()
self._redacted_details_text_document.setHtml(self._details.to_html())
# First set the width,
self._redacted_details_text_document.setTextWidth(self._details_rect.width())
# then get the height of the QTextDocument based on the given width and set
# that + the titles heights + bottom padding as the total height.
if (total_height:=height + self._redacted_details_text_document.size().height() + 10) > self.height():
self.setFixedHeight(total_height)
def _get_actual_geometry(self) -> qtc.QRect:
# Probably not needed for normal desktop environments with window
# managers but I'm an epik i3 user so self.geometry() does not work as
# intended when full screening the window with $mod + F. Or I'm just
# retarded and this is not even a problem.
geometry = self.geometry()
geometry.setTopLeft(qtc.QPoint(0, 0))
return geometry
def paintEvent(self, event: qtg.QPaintEvent) -> None:
total_height = 0
painter = qtg.QPainter(self)
painter.setRenderHint(qtg.QPainter.RenderHint.TextAntialiasing)
painter.drawImage(0, 0, self._thumbnail_image)
painter.save()
painter.setFont(self._title_font)
painter.drawText(
self._title_rects[0], qtc.Qt.TextFlag.TextWordWrap, self._details.title
)
painter.setFont(self._subtitle_font)
painter.drawText(
self._title_rects[1], qtc.Qt.TextFlag.TextWordWrap, self._details.subtitle
)
painter.setFont(self._id_font)
painter.drawText(
self._title_rects[2],
qtc.Qt.TextFlag.TextWordWrap,
str(self._details.id),
)
painter.translate(self._details_rect.topLeft())
painter.setFont(self._redacted_details_font)
self._redacted_details_text_document.drawContents(painter)
painter.restore()
app = qtw.QApplication()
widget = DetailsWidget()
widget.show()
app.exec()
I can display the text and the image next to each other just fine, but the text is not selectable. Looking around for a way to do so, I stumbled upon QGraphicsTextItem. Should I re-do the whole thing in a QGraphicsView instead of using the paintEvent on a QWidget? The reason I'm hesitant to do so is because I don't know of the cons of using a QGraphicsView, maybe it's a lot more resource heavy and not the best for this use case?

Answer 1

You're complicating things unnecessarily.
Just use a basic QHBoxLayout and two QLabels, with the one on the left for the image, and the one on the right for the details.
If you want to allow text selection, use QLabel.setTextInteractionFlags(Qt.TextSelectableByMouse).
An even better solution would be to use a QGraphicsView with a QGraphicsPixmapItem for the image (using fitInView() in the resizeEvent to always show it as large as possible) and a QTextEdit for the details, set in read only mode.
Note that your usage of _get_actual_geometry is wrong in principle (besides the fact that you're calling 4 times in a row, while you could just use a local variable instead), because when a widget has not been shown yet it always has a default size (100x30 for widgets created with a parent, otherwise 640x480), so not only you'll be getting a wrong geometry, but you're also changing it, since setTopLeft() will only move the corner, not translate the rectangle: if you want the basic rectangle of the widget, just use rect(). Obviously, if you properly use layouts as suggested above, this won't be necessary in the first place.