让这个小片段:
import sys
from PyQt5 import QtWidgets
from PyQt5 import QtCore
from PyQt5 import QtGui
from PyQt5.QtWidgets import QMenu
from PyQt5.QtGui import QKeySequence
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QCursor
from PyQt5.QtWidgets import QGraphicsObject
from PyQt5.QtCore import QRectF
from PyQt5.QtGui import QBrush
from PyQt5.QtCore import QPoint
from PyQt5.QtGui import QLinearGradient
from PyQt5.QtGui import QColor
from PyQt5.QtGui import QPen
from PyQt5.QtGui import QPainter
from PyQt5.QtWidgets import QGraphicsTextItem
from PyQt5.QtWidgets import QGraphicsItem
def create_action(parent, text, slot=None,
shortcut=None, shortcuts=None, shortcut_context=None,
icon=None, tooltip=None,
checkable=False, checked=False):
action = QtWidgets.QAction(text, parent)
if icon is not None:
action.setIcon(QIcon(':/%s.png' % icon))
if shortcut is not None:
action.setShortcut(shortcut)
if shortcuts is not None:
action.setShortcuts(shortcuts)
if shortcut_context is not None:
action.setShortcutContext(shortcut_context)
if tooltip is not None:
action.setToolTip(tooltip)
action.setStatusTip(tooltip)
if checkable:
action.setCheckable(True)
if checked:
action.setChecked(True)
if slot is not None:
action.triggered.connect(slot)
return action
class Settings():
WIDTH = 20
HEIGHT = 15
NUM_BLOCKS_X = 32
NUM_BLOCKS_Y = 16
class CI(QGraphicsTextItem):
def __init__(self, text, pos):
QGraphicsTextItem.__init__(self)
self.content = text
self.setPlainText(text)
self.setPos(pos)
self.setTextInteractionFlags(Qt.TextEditorInteraction)
self.setDefaultTextColor(Qt.black)
self.setFlags(
self.flags() | QGraphicsItem.ItemIsMovable | QGraphicsItem.ItemIsSelectable)
self.setZValue(-1)
def paint(self, painter, option, widget):
painter.save()
painter.setBrush(QBrush(Qt.white))
painter.drawRect(self.boundingRect())
painter.restore()
super().paint(painter, option, widget)
def keyPressEvent(self, event):
super().keyPressEvent(event)
self.content = self.toPlainText()
def focusInEvent(self, event):
self.scene().writing_comment = True
# self.setPlainText(self.content)
# print("Focusinevent")
def focusOutEvent(self, event):
self.scene().writing_comment = False
# self.setHtml(self.content)
# print("FocusOutevent")
def contextMenuEvent(self, scme):
super().contextMenuEvent(scme)
class QS(QtWidgets.QGraphicsScene):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
width = Settings.NUM_BLOCKS_X * Settings.WIDTH
height = Settings.NUM_BLOCKS_Y * Settings.HEIGHT
self.setSceneRect(0, 0, width, height)
self.setItemIndexMethod(QtWidgets.QGraphicsScene.NoIndex)
pos = QPoint(
5 * Settings.WIDTH,
2 * Settings.HEIGHT
)
content = """<!DOCTYPE html>
<html>
<body>
<h1>This is heading 1</h1>
<h2>This is heading 2</h2>
<h3>This is heading 3</h3>
<h4>This is heading 4</h4>
<h5>This is heading 5</h5>
<h6>This is heading 6</h6>
</body>
</html>
"""
self.addItem(CI(content, pos))
class QV(QtWidgets.QGraphicsView):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.view_menu = QMenu(self)
self.create_actions()
def create_actions(self):
act = create_action(self.view_menu, "Zoom in",
slot=self.on_zoom_in,
shortcut=QKeySequence("+"), shortcut_context=Qt.WidgetShortcut)
self.view_menu.addAction(act)
act = create_action(self.view_menu, "Zoom out",
slot=self.on_zoom_out,
shortcut=QKeySequence("-"), shortcut_context=Qt.WidgetShortcut)
self.view_menu.addAction(act)
self.addActions(self.view_menu.actions())
def on_zoom_in(self):
if not self.scene():
return
self.scale(1.5, 1.5)
def on_zoom_out(self):
if not self.scene():
return
self.scale(1.0 / 1.5, 1.0 / 1.5)
def drawBackground(self, painter, rect):
painter.setRenderHint(QPainter.Antialiasing, True)
gr = rect.toRect()
start_x = gr.left() + Settings.WIDTH - (gr.left() % Settings.WIDTH)
start_y = gr.top() + Settings.HEIGHT - (gr.top() % Settings.HEIGHT)
painter.save()
for index, x in enumerate(range(start_x, gr.right(), Settings.WIDTH)):
if index == Settings.NUM_BLOCKS_X:
painter.setPen(QtGui.QColor(255, 70, 80).lighter(90))
painter.setOpacity(0.7)
else:
painter.setPen(QtGui.QColor(60, 70, 80).lighter(90))
painter.setOpacity(0.7)
painter.drawLine(x, gr.top(), x, gr.bottom())
for index, y in enumerate(range(start_y, gr.bottom(), Settings.HEIGHT)):
if index == Settings.NUM_BLOCKS_Y:
painter.setPen(QtGui.QColor(255, 70, 80).lighter(90))
painter.setOpacity(0.7)
else:
painter.setPen(QtGui.QColor(60, 70, 80).lighter(90))
painter.setOpacity(0.7)
painter.drawLine(gr.left(), y, gr.right(), y)
painter.restore()
super().drawBackground(painter, rect)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
a = QS()
b = QV()
b.setScene(a)
print(b.mapToScene(b.rect()))
b.show()
sys.exit(app.exec_())
如果运行它，我们将看到它正在创建一个带有网格和QGraphicsTextItem的小场景，如下所示:
我要在这里弄清楚的是，每当我移动QGraphicsTextItem或更改的大小时，如何在网格交叉点上捕捉QGraphicsTextItem(当我编写一些文本时)，如何保证呢？这是一张小图，可以更好地解释我想要什么:
最佳答案
要设置QGraphicsTextItem的新宽度和高度，您可以覆盖boundingRect()，对于setPos()，您可以使用任何适当的事件(例如MouseReleaseEvent或MouseMoveEvent)，并根据最后一个pos()计算左上角的下一个网格交集:
class CI(QGraphicsTextItem):
def __init__(self, text, pos):
QGraphicsTextItem.__init__(self)
self.content = text
self.setPlainText(text)
self.setPos(pos)
self.setTextInteractionFlags(Qt.TextEditorInteraction)
self.setDefaultTextColor(Qt.black)
self.setFlags(
self.flags() | QGraphicsItem.ItemIsMovable | QGraphicsItem.ItemIsSelectable)
self.setZValue(-1)
def boundingRect(self):
# get the original width and height of boundingrect
br = QGraphicsTextItem.boundingRect(self)
brw = br.width()
brh = br.height()
# new width and height in "blocks"
wblocks = int(brw/Settings.WIDTH) + 1
hblocks = int(brh/Settings.HEIGHT) + 1
w = wblocks*Settings.WIDTH
h = hblocks*Settings.HEIGHT
return QtCore.QRectF(0, 0, w, h)
def mouseReleaseEvent(self, event):
# QGraphicsItem.mouseReleaseEvent(self, event)
QGraphicsTextItem.mouseReleaseEvent(self, event)
self.setGridIntersection(self.pos())
def mouseMoveEvent(self, event):
QGraphicsTextItem.mouseMoveEvent(self, event)
self.setGridIntersection(self.pos())
def setGridIntersection(self, pos):
# get the next grid intersection top left of items top-left corner
grid_x = int(pos.x()/Settings.WIDTH)
grid_y = int(pos.y()/Settings.HEIGHT)
self.setPos(grid_x*Settings.WIDTH, grid_y*Settings.HEIGHT)
def paint(self, painter, option, widget):
painter.save()
painter.setBrush(QBrush(Qt.white))
painter.drawRect(self.boundingRect())
painter.restore()
super().paint(painter, option, widget)
def keyPressEvent(self, event):
super().keyPressEvent(event)
self.content = self.toPlainText()
def focusInEvent(self, event):
self.scene().writing_comment = True
# self.setPlainText(self.content)
# print("Focusinevent")
def focusOutEvent(self, event):
self.scene().writing_comment = False
# self.setHtml(self.content)
# print("FocusOutevent")
def contextMenuEvent(self, scme):
super().contextMenuEvent(scme)
编辑01.02.17:
上面的解决方案仅适用于单选，单选和多选都可以使用:
class CI(QGraphicsTextItem):
def __init__(self, text, pos):
QGraphicsTextItem.__init__(self)
self.content = text
self.setPlainText(text)
self.setPos(pos)
self.setTextInteractionFlags(Qt.TextEditorInteraction)
self.setDefaultTextColor(Qt.black)
self.setFlags(
self.flags() | QGraphicsItem.ItemIsMovable | QGraphicsItem.ItemIsSelectable)
self.setZValue(-1)
self.setAcceptDrops(True)
def boundingRect(self):
# get the original width and height of boundingrect
br = QGraphicsTextItem.boundingRect(self)
brw = br.width()
brh = br.height()
# new width and height in "blocks"
wblocks = int(brw / Settings.WIDTH) + 1
hblocks = int(brh / Settings.HEIGHT) + 1
w = wblocks * Settings.WIDTH
h = hblocks * Settings.HEIGHT
return QtCore.QRectF(0, 0, w, h)
def setGridIntersection(self, pos):
# get the next grid intersection top left of items top-left corner
grid_x = int(pos.x() / Settings.WIDTH)
grid_y = int(pos.y() / Settings.HEIGHT)
self.setPos(grid_x * Settings.WIDTH, grid_y * Settings.HEIGHT)
def paint(self, painter, option, widget):
painter.save()
painter.setBrush(QBrush(Qt.white))
painter.drawRect(self.boundingRect())
painter.restore()
super().paint(painter, option, widget)
def keyPressEvent(self, event):
super().keyPressEvent(event)
self.content = self.toPlainText()
def focusInEvent(self, event):
self.scene().writing_comment = True
# self.setPlainText(self.content)
# print("Focusinevent")
def focusOutEvent(self, event):
self.scene().writing_comment = False
# self.setHtml(self.content)
# print("FocusOutevent")
def contextMenuEvent(self, scme):
super().contextMenuEvent(scme)
并在QS类中添加:
def mouseMoveEvent(self, event):
QtWidgets.QGraphicsScene.mouseMoveEvent(self, event)
for i in self.selectedItems():
if type(i) == CI:
i.setGridIntersection(i.pos())