PyGobject（八十二）Drag and Drop

Drag信号

Drop信号

例子

在部件之间进行拖放，一般需要设置一个拖动源（拖动什么部件），使用Gtk.Widget.drag_source_set（）方法，设置一个拖动目标（部件拖放到什么地方），使用Gtk.Widget.drag_dest_set（）方法。

有些部件提供了特殊的方法来替代这两个方法，如 Gtk.TreeView 和 Gtk.IconView，它们提供enable_model_drag_source(start_button_mask, targets, actions)来设置拖动源。

为了在源和目的地之间传输数据，需要在“drag-data-get” 和 “drag-data-received”信号中的Gtk.SelectionData变量中进行set和get数据

Drag信号

Name	When it is emitted	Common Purpose
drag-begin	User starts a drag	Set-up drag icon
drag-data-get	When drag data is requested by the destination	Transfer drag data from source to destination
drag-data-delete	When a drag with the action Gdk.DragAction.MOVE is completed	Delete data from the source to complete the ‘move’
drag-end	When the drag is complete	Undo anything done in drag-begin

Drop信号

Name	When it is emitted	Common Purpose
drag-motion	Drag icon moves over a drop area	Allow only certain areas to be dropped onto
drag-drop	Icon is dropped onto a drag area	Allow only certain areas to be dropped onto
drag-data-received	When drag data is received by the destination	Transfer drag data from source to destination

例子

代码：

#!/usr/bin/env python3
# Created by xiaosanyu at 16/6/16
# section 130
TITLE = "Drag and Drop"
DESCRIPTION = ""
import gi

gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Gdk, GdkPixbuf

(TARGET_ENTRY_TEXT, TARGET_ENTRY_PIXBUF, TARGET_ENTRY_ALL) = range(3)
(COLUMN_TEXT, COLUMN_PIXBUF, COLUMN_NAME) = range(3)

DRAG_ACTION = Gdk.DragAction.COPY

atom_text = Gdk.atom_intern('UTF8_STRING', False)
atom_pixbuf = Gdk.atom_intern('image/png', False)
text_entry = Gtk.TargetEntry.new("UTF8_STRING", Gtk.TargetFlags.SAME_APP, TARGET_ENTRY_ALL)
pixbuf_entry = Gtk.TargetEntry.new("image/png", Gtk.TargetFlags.SAME_APP, TARGET_ENTRY_ALL)

class DragDropWindow(Gtk.Window):
def __init__(self):
Gtk.Window.__init__(self, title="Drag and Drop Demo")

vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=6)
self.add(vbox)

hbox = Gtk.Box(spacing=12)
vbox.pack_start(hbox, True, True, 0)

self.iconview = DragSourceIconView()
self.drop_area = DropArea()

hbox.pack_start(self.iconview, True, True, 0)
hbox.pack_start(self.drop_area, True, True, 0)

button_box = Gtk.Box(spacing=6)
vbox.pack_start(button_box, True, False, 0)

image_button = Gtk.RadioButton.new_with_label_from_widget(None,
"Images")
image_button.connect("toggled", self.add_image_targets)
button_box.pack_start(image_button, True, False, 0)

text_button = Gtk.RadioButton.new_with_label_from_widget(image_button,
"Text")
text_button.connect("toggled", self.add_text_targets)
button_box.pack_start(text_button, True, False, 0)

all_button = Gtk.RadioButton.new_with_label_from_widget(image_button,
"ALL")
all_button.connect("toggled", self.add_all)
button_box.pack_start(all_button, True, False, 0)

# self.add_image_targets()

def add_image_targets(self, button=None):
if button is None or button.get_active():
targets = Gtk.TargetList.new([])
targets.add_image_targets(TARGET_ENTRY_PIXBUF, True)

self.drop_area.drag_dest_set_target_list(targets)
self.iconview.drag_source_set_target_list(targets)

def add_text_targets(self, button=None):
if button is None or button.get_active():
self.drop_area.drag_dest_set_target_list(None)
self.iconview.drag_source_set_target_list(None)

self.drop_area.drag_dest_add_text_targets()
self.iconview.drag_source_add_text_targets()

def add_all(self, button=None):
if button is None or button.get_active():
targets = Gtk.TargetList.new([text_entry])
self.drop_area.drag_dest_set_target_list(targets)
self.iconview.drag_source_set_target_list(targets)
print(targets.find(atom_text), targets.find(atom_pixbuf))

class DragSourceIconView(Gtk.IconView):
def __init__(self):
Gtk.IconView.__init__(self)
self.set_text_column(COLUMN_TEXT)
self.set_pixbuf_column(COLUMN_PIXBUF)

model = Gtk.ListStore(str, GdkPixbuf.Pixbuf, str)
self.set_model(model)
self.add_item("Item 1", "image-missing")
self.add_item("Item 2", "help-about")
self.add_item("Item 3", "edit-copy")

self.enable_model_drag_source(Gdk.ModifierType.BUTTON1_MASK, [],
DRAG_ACTION)
self.connect("drag-data-get", self.on_drag_data_get)

def on_drag_data_get(self, widget, drag_context, data, info, time):
selected_path = self.get_selected_items()[0]
selected_iter = self.get_model().get_iter(selected_path)
if info == TARGET_ENTRY_TEXT:
text = self.get_model().get_value(selected_iter, COLUMN_TEXT)
data.set_text(text, -1)
elif info == TARGET_ENTRY_PIXBUF:
pixbuf = self.get_model().get_value(selected_iter, COLUMN_PIXBUF)
data.set_pixbuf(pixbuf)
elif info == TARGET_ENTRY_ALL:
text = self.get_model().get_value(selected_iter, COLUMN_TEXT)
name = self.get_model().get_value(selected_iter, COLUMN_NAME)
data.set(atom_text, 8, (text + ";" + name).encode())
# print(data.set_text(text + ";" + name, -1))
# print(data.set_pixbuf(pixbuf))

def add_item(self, text, icon_name):
pixbuf = Gtk.IconTheme.get_default().load_icon(icon_name, 16, 0)
self.get_model().append([text, pixbuf, icon_name])

class DropArea(Gtk.IconView):
def __init__(self):
Gtk.IconView.__init__(self)
self.set_text_column(COLUMN_TEXT)
self.set_pixbuf_column(COLUMN_PIXBUF)

self.model = Gtk.ListStore(str, GdkPixbuf.Pixbuf)
self.set_model(self.model)
self.model.append(["Drop something on me!", None])

self.drag_dest_set(Gtk.DestDefaults.ALL, [], DRAG_ACTION)
self.enable_model_drag_dest([], DRAG_ACTION)

self.connect("drag-data-received", self.on_drag_data_received)

def on_drag_data_received(self, widget, drag_context, x, y, data, info, time):

if info == TARGET_ENTRY_TEXT:
text = data.get_text()
self.model[0][0] = text
print("Received text: %s" % text)

elif info == TARGET_ENTRY_PIXBUF:
pixbuf = data.get_pixbuf()
width = pixbuf.get_width()
height = pixbuf.get_height()
self.model[0][1] = pixbuf
print("Received pixbuf with width %spx and height %spx" % (width, height))
elif info == TARGET_ENTRY_ALL:
text = data.get_text().split(";")
# pixbuf = data.get_pixbuf()
pixbuf = Gtk.IconTheme.get_default().load_icon(text[1], 16, 0)
self.model[0][0] = text[0]
self.model[0][1] = pixbuf

def main():
win = DragDropWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()

if __name__ == "__main__":
main()

代码下载地址：http://download.csdn.net/detail/a87b01c14/9594728