I'm trying to click and drag to zoom in and out of a QGraphicsView like you see in graphics applications like Maya and Nuke. There is a lot of information about using the mouse wheel but I haven't found anything related to dragging to zoom.
Is there an easy way to do this or do I need to roll my own implementation of the "anchor" effect?
The following will work but the view follows the mouse around as I drag the zoom rather than appearing to zoom in and out of a fixed point in space (the point where the mouse was clicked to start the drag-zoom.
(This is a bunch of copy and paste from my more complex source code. It is intended to be illustrative though it should run)
def mousePressEvent(self, event):
self.press_mouse_pos = event.pos()
transform = self.transform()
self.press_translate = [transform.m31(), transform.m32()]
self.press_scale = transform.m11()
if event.button() == QtCore.Qt.RightButton and \
event.modifiers() == QtCore.Qt.AltModifier:
self.scaling = True
event.accept()
else:
super(GraphView, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self.scaling:
delta_pos = event.pos() - self.press_mouse_pos
amount = delta_pos.x() + delta_pos.y()
speed = 0.001
scl = self.press_scale - (amount * speed)
scl = min(1.0, max(scl, 0.1)) # Clamp so we don't go to far in or out
transform = QtGui.QTransform(
scl, 0, 0,
0, scl, 0,
self.press_translate[0], self.press_translate[1], 1
)
# If interactive is True then some double calculations are triggered
prev_interactive_state = self.isInteractive()
prev_anchor_mode = self.transformationAnchor()
self.setInteractive(False)
self.setTransformationAnchor(QtGui.QGraphicsView.AnchorUnderMouse)
self.setTransform(transform)
self.setInteractive(prev_interactive_state)
self.setTransformationAnchor(prev_anchor_mode)
else:
super(GraphView, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
self.scaling = False
super(GraphView, self).mouseReleaseEvent(event)
Change this:
self.setTransformationAnchor(QtGui.QGraphicsView.AnchorUnderMouse)
to that:
self.setTransformationAnchor(QtGui.QGraphicsView.NoAnchor)
setTransformation() is a subject to transformation anchor; AnchorUnderMouse makes sure that a scene point corresponding the current (at the moment when transform is applied) mouse position remains untranslated.
Related
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?
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.
Good night.
I have seen some programs with new borderless designs and still you can make use of resizing.
At the moment I know that to remove the borders of a pyqt program we use:
QtCore.Qt.FramelessWindowHint
And that to change the size of a window use QSizeGrip.
But how can we resize a window without borders?
This is the code that I use to remove the border of a window but after that I have not found information on how to do it in pyqt5.
I hope you can help me with an example of how to solve this problem
from PyQt5.QtWidgets import QMainWindow,QApplication
from PyQt5 import QtCore
class Main(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
app = QApplication([])
m = Main()
m.show()
m.resize(800,600)
app.exec_()
If you use a QMainWindow you can add a QStatusBar (which automatically adds a QSizeGrip) just by calling statusBar():
This function creates and returns an empty status bar if the status bar does not exist.
Otherwise, you can manually add grips, and their interaction is done automatically based on their position. In the following example I'm adding 4 grips, one for each corner, and then I move them each time the window is resized.
class Main(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.gripSize = 16
self.grips = []
for i in range(4):
grip = QSizeGrip(self)
grip.resize(self.gripSize, self.gripSize)
self.grips.append(grip)
def resizeEvent(self, event):
QMainWindow.resizeEvent(self, event)
rect = self.rect()
# top left grip doesn't need to be moved...
# top right
self.grips[1].move(rect.right() - self.gripSize, 0)
# bottom right
self.grips[2].move(
rect.right() - self.gripSize, rect.bottom() - self.gripSize)
# bottom left
self.grips[3].move(0, rect.bottom() - self.gripSize)
UPDATE
Based on comments, also side-resizing is required. To do so a good solution is to create a custom widget that behaves similarly to QSizeGrip, but for vertical/horizontal resizing only.
For better implementation I changed the code above, used a gripSize to construct an "inner" rectangle and, based on it, change the geometry of all widgets, for both corners and sides.
Here you can see the "outer" rectangle and the "inner" rectangle used for geometry computations:
Then you can create all geometries, for QSizeGrip widgets (in light blue):
And for custom side widgets:
from PyQt5 import QtCore, QtGui, QtWidgets
class SideGrip(QtWidgets.QWidget):
def __init__(self, parent, edge):
QtWidgets.QWidget.__init__(self, parent)
if edge == QtCore.Qt.LeftEdge:
self.setCursor(QtCore.Qt.SizeHorCursor)
self.resizeFunc = self.resizeLeft
elif edge == QtCore.Qt.TopEdge:
self.setCursor(QtCore.Qt.SizeVerCursor)
self.resizeFunc = self.resizeTop
elif edge == QtCore.Qt.RightEdge:
self.setCursor(QtCore.Qt.SizeHorCursor)
self.resizeFunc = self.resizeRight
else:
self.setCursor(QtCore.Qt.SizeVerCursor)
self.resizeFunc = self.resizeBottom
self.mousePos = None
def resizeLeft(self, delta):
window = self.window()
width = max(window.minimumWidth(), window.width() - delta.x())
geo = window.geometry()
geo.setLeft(geo.right() - width)
window.setGeometry(geo)
def resizeTop(self, delta):
window = self.window()
height = max(window.minimumHeight(), window.height() - delta.y())
geo = window.geometry()
geo.setTop(geo.bottom() - height)
window.setGeometry(geo)
def resizeRight(self, delta):
window = self.window()
width = max(window.minimumWidth(), window.width() + delta.x())
window.resize(width, window.height())
def resizeBottom(self, delta):
window = self.window()
height = max(window.minimumHeight(), window.height() + delta.y())
window.resize(window.width(), height)
def mousePressEvent(self, event):
if event.button() == QtCore.Qt.LeftButton:
self.mousePos = event.pos()
def mouseMoveEvent(self, event):
if self.mousePos is not None:
delta = event.pos() - self.mousePos
self.resizeFunc(delta)
def mouseReleaseEvent(self, event):
self.mousePos = None
class Main(QtWidgets.QMainWindow):
_gripSize = 8
def __init__(self):
QtWidgets.QMainWindow.__init__(self)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.sideGrips = [
SideGrip(self, QtCore.Qt.LeftEdge),
SideGrip(self, QtCore.Qt.TopEdge),
SideGrip(self, QtCore.Qt.RightEdge),
SideGrip(self, QtCore.Qt.BottomEdge),
]
# corner grips should be "on top" of everything, otherwise the side grips
# will take precedence on mouse events, so we are adding them *after*;
# alternatively, widget.raise_() can be used
self.cornerGrips = [QtWidgets.QSizeGrip(self) for i in range(4)]
#property
def gripSize(self):
return self._gripSize
def setGripSize(self, size):
if size == self._gripSize:
return
self._gripSize = max(2, size)
self.updateGrips()
def updateGrips(self):
self.setContentsMargins(*[self.gripSize] * 4)
outRect = self.rect()
# an "inner" rect used for reference to set the geometries of size grips
inRect = outRect.adjusted(self.gripSize, self.gripSize,
-self.gripSize, -self.gripSize)
# top left
self.cornerGrips[0].setGeometry(
QtCore.QRect(outRect.topLeft(), inRect.topLeft()))
# top right
self.cornerGrips[1].setGeometry(
QtCore.QRect(outRect.topRight(), inRect.topRight()).normalized())
# bottom right
self.cornerGrips[2].setGeometry(
QtCore.QRect(inRect.bottomRight(), outRect.bottomRight()))
# bottom left
self.cornerGrips[3].setGeometry(
QtCore.QRect(outRect.bottomLeft(), inRect.bottomLeft()).normalized())
# left edge
self.sideGrips[0].setGeometry(
0, inRect.top(), self.gripSize, inRect.height())
# top edge
self.sideGrips[1].setGeometry(
inRect.left(), 0, inRect.width(), self.gripSize)
# right edge
self.sideGrips[2].setGeometry(
inRect.left() + inRect.width(),
inRect.top(), self.gripSize, inRect.height())
# bottom edge
self.sideGrips[3].setGeometry(
self.gripSize, inRect.top() + inRect.height(),
inRect.width(), self.gripSize)
def resizeEvent(self, event):
QtWidgets.QMainWindow.resizeEvent(self, event)
self.updateGrips()
app = QtWidgets.QApplication([])
m = Main()
m.show()
m.resize(240, 160)
app.exec_()
to hide the QSizeGrip on the corners where they shouldn't be showing, you can just change the background color of the QSizeGrip to camouflage them to the background. add this to each of the corners of musicamante's answer:
self.cornerGrips[0].setStyleSheet("""
background-color: transparent;
""")
Currently, QTextEdit permits selecting text and then altering that selection with shift-click-drag only on the side of the selection opposite the anchor. The anchor is placed where the selection started. If the user tries to alter the selection near the start, the selection pivots around the anchor point instead of extending. I'd like to permit changing the selection from either side.
My first attempt is to simply set the anchor on the opposite side from where the cursor is located. Say, for example, the selection is from 10 to 20. If the cursor is shift-click-dragged at position 8, then the anchor would be set to 20. If the cursor is shift-click-dragged at position 22, then the anchor would be set to 10. Later, I'll try something more robust, perhaps based on the center point of the selection.
I thought this code would work, but it does not seem to affect the default behavior at all. What have I missed?
import sys
from PySide.QtCore import *
from PySide.QtGui import *
class TextEditor(QTextEdit):
def __init__(self, parent=None):
super().__init__(parent)
self.setReadOnly(True)
self.setMouseTracking(True)
def mouseMoveEvent(self, event):
point = QPoint()
x = event.x() #these are relative to the upper left corner of the text edit window
y = event.y()
point.setX(x)
point.setY(y)
self.mousepos = self.cursorForPosition(point).position() # get character position of current mouse using local window coordinates
if event.buttons()==Qt.LeftButton:
modifiers = QApplication.keyboardModifiers()
if modifiers == Qt.ShiftModifier:
start = -1 #initialize to something impossible
end = -1
cursor = self.textCursor()
select_point1 = cursor.selectionStart()
select_point2 = cursor.selectionEnd()
if select_point1 < select_point2: # determine order of selection points
start = select_point1
end = select_point2
elif select_point2 < select_point1:
start = select_point2
end = select_point1
if self.mousepos > end: # if past end when shift-click then trying to extend right
cursor.setPosition(start, mode=QTextCursor.MoveAnchor)
elif self.mousepos < start: # if before start when shift-click then trying to extend left
cursor.setPosition(end, mode=QTextCursor.MoveAnchor)
if start != -1 and end != -1: #if selection exists then this should trigger
self.setTextCursor(cursor)
super().mouseMoveEvent(event)
Here's a first stab at implementing shift+click extension of the current selection. It seems to work okay, but I have not tested it to death, so there may be one or two glitches. The intended behaviour is that a shift+click above or below the selection should extend the whole selection in that direction; and a shift+click with drag should do the same thing, only continuously.
Note that I have also set the text-interaction flags so that the caret is visible in read-only mode, and the selection can also be manipulated with the keyboard in various ways (e.g. ctrl+shift+right extends the selection to the next word).
import sys
from PySide.QtCore import *
from PySide.QtGui import *
class TextEditor(QTextEdit):
def __init__(self, parent=None):
super().__init__(parent)
self.setReadOnly(True)
self.setTextInteractionFlags(
Qt.TextSelectableByMouse |
Qt.TextSelectableByKeyboard)
def mouseMoveEvent(self, event):
if not self.setShiftSelection(event, True):
super().mouseMoveEvent(event)
def mousePressEvent(self, event):
if not self.setShiftSelection(event):
super().mousePressEvent(event)
def setShiftSelection(self, event, moving=False):
if (event.buttons() == Qt.LeftButton and
QApplication.keyboardModifiers() == Qt.ShiftModifier):
cursor = self.textCursor()
start = cursor.selectionStart()
end = cursor.selectionEnd()
if not moving or start != end:
anchor = cursor.anchor()
pos = self.cursorForPosition(event.pos()).position()
if pos <= start:
start = pos
elif pos >= end:
end = pos
elif anchor == start:
end = pos
else:
start = pos
if pos <= anchor:
start, end = end, start
cursor.setPosition(start, QTextCursor.MoveAnchor)
cursor.setPosition(end, QTextCursor.KeepAnchor)
self.setTextCursor(cursor)
return True
return False
if __name__ == '__main__':
app = QApplication(sys.argv)
window = TextEditor()
window.setText(open(__file__).read())
window.setGeometry(600, 50, 800, 800)
window.show()
sys.exit(app.exec_())
I am working on a simple 3D viewer using PyQt and its bindings for OpenGL. I would like to implement the following user actions (like for example in solidworks):
pan/translate: with combination ctrl+middle mouse button (pressed)
rotate: middle mouse button (pressed)
and moving mouse. The code is:
def mousePressEvent(self, event):
self.last_pos = event.posF()
def mouseMoveEvent(self, event):
dxy = event.posF() - self.last_pos
dx = dxy.x() / self.width()
dy = dxy.y() / self.height()
# rotate -
if event.buttons() & Qt.MidButton:
self.camera.rotate(dx, dy)
# translate/pan
elif (event.buttons() & Qt.MidButton) and (event.modifiers() & Qt.ControlModifier):
self.camera.pan(dx, dy)
# zoom
self.last_pos = event.posF()
The problem I have is that when I press ctrl and then middle mouse button both (self.camera.rotate(dx, dy) and self.camera.pan(dx, dy)) functions are executed, but I would like just to translate the object(s). I would like to ask you is there a way how can the code be modified that translate and rotate will work with the desires key combinations. Right now I do not have any ideas.
Both actions require the middle button. But only pan/translate requires Ctrl, so use that to switch between them:
if event.buttons() & Qt.MidButton:
if event.modifiers() & Qt.ControlModifier:
self.camera.pan(dx, dy)
else:
self.camera.rotate(dx, dy)
I have a QGraphicsScene and its associated QGraphicsView. I let the user create some shapes in the form of derived QGraphicsItems into that scene. I also want them to be movable by mouse. Clicking one or more items select them, and moving them around while the mouse button is pressed works. I inherited QGraphicsView to do this, and overrided mousePressedEvent, mouseReleasedEvent & mouseMoveEvent to achieve this. When the user clicks, I am basically testing if an item (accessed through items() which returns the items of the associated scene) is under the mouse with contains(), and if it is then I am selecting it.
In the mouseMoveEvent, I am using setPos() on each item of the selection to move it relatively to the mouse move. It works and displays as expected.
This may not be the most efficient way, but that's what I achieved while discovering Qt. Now, the problem is : once I've moved my item or group of items with the mouse, if I want to deselect them (by clicking again on them), the contains() method supplied with the position of the input acts as if the item wasn't moved. Example : I draw a rectangle in the upper left corner, and move it around to, say, the center of the view. Clicking on it again doesn't work but clicking on where it was initially works. So I suspect it has something to do with local and global coordinates.
I've run through several problems today (most of them resolved) but I'm stuck on this one.
Here's my View class :
class CustomGraphicsView(QGraphicsView):
def __init__(self, *args):
super().__init__(*args)
self.selection = []
self.offsets = []
self.select_point = None
def mousePressEvent(self, event):
pos = self.mapFromGlobal(event.globalPos())
modifiers = event.modifiers()
if event.button() == Qt.LeftButton:
#do something else
elif event.button() == Qt.RightButton:
self.select_point = pos
for s in self.selection:
if s.contains(pos): # deselect or drag
for s in self.selection: # construct the offsets for dragging
self.offsets = [s.pos() - pos for s in self.selection]
break
def mouseReleaseEvent(self, event):
pos = self.mapFromGlobal(event.globalPos())
modifiers = event.modifiers()
if event.button() == Qt.LeftButton:
#do something else
elif event.button() == Qt.RightButton:
if self.select_point == pos: # one click selection
self.update_selection(pos)
if self.offsets:
self.offsets.clear()
def mouseMoveEvent(self, event):
pos = self.mapFromGlobal(event.globalPos())
modifiers = event.modifiers()
if event.buttons() == Qt.RightButton:
if not self.offsets:
for s in self.selection:
self.offsets = [s.pos() - pos for s in self.selection]
for s, off in zip(self.selection, self.offsets):
s.set_pos(pos + off)
def update_selection(self, pos):
for item in self.items():
if not item.contains(pos):
continue
if item.selected:
self.selection.remove(item)
else:
self.selection.append(item)
item.select()
break
The scene rect is set at (0;0) so there's no concern about moving it or whatever.