1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#include "qfocusframe.h"
5#include "qstyle.h"
6#include "qbitmap.h"
7#include "qstylepainter.h"
8#include "qstyleoption.h"
9#include "qdebug.h"
10#include <private/qwidget_p.h>
11
12QT_BEGIN_NAMESPACE
13
14class QFocusFramePrivate : public QWidgetPrivate
15{
16 Q_DECLARE_PUBLIC(QFocusFrame)
17 QWidget *widget;
18 QWidget *frameParent;
19 bool showFrameAboveWidget;
20public:
21 QFocusFramePrivate() {
22 widget = nullptr;
23 frameParent = nullptr;
24 sendChildEvents = false;
25 showFrameAboveWidget = false;
26 }
27 void updateSize();
28 void update();
29};
30
31void QFocusFramePrivate::update()
32{
33 Q_Q(QFocusFrame);
34 q->setParent(frameParent);
35 updateSize();
36 if (q->parentWidget()->rect().intersects(r: q->geometry())) {
37 if (showFrameAboveWidget)
38 q->raise();
39 else
40 q->stackUnder(widget);
41 q->show();
42 } else {
43 q->hide();
44 }
45}
46
47void QFocusFramePrivate::updateSize()
48{
49 Q_Q(QFocusFrame);
50 if (!widget)
51 return;
52
53 QStyleOption opt;
54 q->initStyleOption(option: &opt);
55 int vmargin = q->style()->pixelMetric(metric: QStyle::PM_FocusFrameVMargin, option: &opt, widget: q),
56 hmargin = q->style()->pixelMetric(metric: QStyle::PM_FocusFrameHMargin, option: &opt, widget: q);
57 QPoint pos(widget->x(), widget->y());
58 if (q->parentWidget() != widget->parentWidget())
59 pos = widget->parentWidget()->mapTo(q->parentWidget(), pos);
60 QRect geom(pos.x()-hmargin, pos.y()-vmargin,
61 widget->width()+(hmargin*2), widget->height()+(vmargin*2));
62 if (q->geometry() == geom)
63 return;
64
65 q->setGeometry(geom);
66
67 opt.rect = q->rect();
68 QStyleHintReturnMask mask;
69 if (q->style()->styleHint(stylehint: QStyle::SH_FocusFrame_Mask, opt: &opt, widget: q, returnData: &mask))
70 q->setMask(mask.region);
71}
72
73/*!
74 Initialize \a option with the values from this QFocusFrame. This method is useful
75 for subclasses when they need a QStyleOption, but don't want to fill
76 in all the information themselves.
77
78 \sa QStyleOption::initFrom()
79*/
80void QFocusFrame::initStyleOption(QStyleOption *option) const
81{
82 if (!option)
83 return;
84
85 option->initFrom(w: this);
86}
87
88/*!
89 \class QFocusFrame
90 \brief The QFocusFrame widget provides a focus frame which can be
91 outside of a widget's normal paintable area.
92
93 \ingroup basicwidgets
94 \inmodule QtWidgets
95
96 Normally an application will not need to create its own
97 QFocusFrame as QStyle will handle this detail for
98 you. A style writer can optionally use a QFocusFrame to have a
99 focus area outside of the widget's paintable geometry. In this way
100 space need not be reserved for the widget to have focus but only
101 set on a QWidget with QFocusFrame::setWidget. It is, however,
102 legal to create your own QFocusFrame on a custom widget and set
103 its geometry manually via QWidget::setGeometry however you will
104 not get auto-placement when the focused widget changes size or
105 placement.
106*/
107
108/*!
109 Constructs a QFocusFrame.
110
111 The focus frame will not monitor \a parent for updates but rather
112 can be placed manually or by using QFocusFrame::setWidget. A
113 QFocusFrame sets Qt::WA_NoChildEventsForParent attribute; as a
114 result the parent will not receive a QEvent::ChildAdded event,
115 this will make it possible to manually set the geometry of the
116 QFocusFrame inside of a QSplitter or other child event monitoring
117 widget.
118
119 \sa QFocusFrame::setWidget()
120*/
121
122QFocusFrame::QFocusFrame(QWidget *parent)
123 : QWidget(*new QFocusFramePrivate, parent, { })
124{
125 setAttribute(Qt::WA_TransparentForMouseEvents);
126 setFocusPolicy(Qt::NoFocus);
127 setAttribute(Qt::WA_NoChildEventsForParent, on: true);
128 setAttribute(Qt::WA_AcceptDrops, on: style()->styleHint(stylehint: QStyle::SH_FocusFrame_AboveWidget, opt: nullptr, widget: this));
129}
130
131/*!
132 Destructor.
133*/
134
135QFocusFrame::~QFocusFrame()
136{
137}
138
139/*!
140 QFocusFrame will track changes to \a widget and resize itself automatically.
141 If the monitored widget's parent changes, QFocusFrame will follow the widget
142 and place itself around the widget automatically. If the monitored widget is deleted,
143 QFocusFrame will set it to zero.
144
145 \sa QFocusFrame::widget()
146*/
147
148void
149QFocusFrame::setWidget(QWidget *widget)
150{
151 Q_D(QFocusFrame);
152
153 if (style()->styleHint(stylehint: QStyle::SH_FocusFrame_AboveWidget, opt: nullptr, widget: this))
154 d->showFrameAboveWidget = true;
155 else
156 d->showFrameAboveWidget = false;
157
158 if (widget == d->widget)
159 return;
160 if (d->widget) {
161 // Remove event filters from the widget hierarchy.
162 QWidget *p = d->widget;
163 do {
164 p->removeEventFilter(obj: this);
165 if (!d->showFrameAboveWidget || p == d->frameParent)
166 break;
167 p = p->parentWidget();
168 }while (p);
169 }
170 if (widget && !widget->isWindow() && widget->parentWidget()->windowType() != Qt::SubWindow) {
171 d->widget = widget;
172 d->widget->installEventFilter(filterObj: this);
173 QWidget *p = widget->parentWidget();
174 QWidget *prev = nullptr;
175 if (d->showFrameAboveWidget) {
176 // Find the right parent for the focus frame.
177 while (p) {
178 // Traverse the hirerarchy of the 'widget' for setting event filter.
179 // During this if come across toolbar or a top level, use that
180 // as the parent for the focus frame. If we find a scroll area
181 // use its viewport as the parent.
182 bool isScrollArea = false;
183 if (p->isWindow() || p->inherits(classname: "QToolBar") || (isScrollArea = p->inherits(classname: "QAbstractScrollArea"))) {
184 d->frameParent = p;
185 // The previous one in the hierarchy will be the viewport.
186 if (prev && isScrollArea)
187 d->frameParent = prev;
188 break;
189 } else {
190 p->installEventFilter(filterObj: this);
191 prev = p;
192 p = p->parentWidget();
193 }
194 }
195 } else {
196 d->frameParent = p;
197 }
198 d->update();
199 } else {
200 d->widget = nullptr;
201 hide();
202 }
203}
204
205/*!
206 Returns the currently monitored widget for automatically resize and
207 update.
208
209 \sa QFocusFrame::setWidget()
210*/
211
212QWidget *
213QFocusFrame::widget() const
214{
215 Q_D(const QFocusFrame);
216 return d->widget;
217}
218
219
220/*! \reimp */
221void
222QFocusFrame::paintEvent(QPaintEvent *)
223{
224 Q_D(QFocusFrame);
225
226 if (!d->widget)
227 return;
228
229 QStylePainter p(this);
230 QStyleOption option;
231 initStyleOption(option: &option);
232 const int vmargin = style()->pixelMetric(metric: QStyle::PM_FocusFrameVMargin, option: &option, widget: this);
233 const int hmargin = style()->pixelMetric(metric: QStyle::PM_FocusFrameHMargin, option: &option, widget: this);
234 QWidgetPrivate *wd = qt_widget_private(widget: d->widget);
235 QRect rect = wd->clipRect().adjusted(xp1: 0, yp1: 0, xp2: hmargin*2, yp2: vmargin*2);
236 p.setClipRect(rect);
237 p.drawControl(ce: QStyle::CE_FocusFrame, opt: option);
238}
239
240
241/*! \reimp */
242bool
243QFocusFrame::eventFilter(QObject *o, QEvent *e)
244{
245 Q_D(QFocusFrame);
246 if (o == d->widget) {
247 switch(e->type()) {
248 case QEvent::Move:
249 case QEvent::Resize:
250 d->updateSize();
251 break;
252 case QEvent::Hide:
253 case QEvent::StyleChange:
254 hide();
255 break;
256 case QEvent::ParentChange:
257 if (d->showFrameAboveWidget) {
258 QWidget *w = d->widget;
259 setWidget(nullptr);
260 setWidget(w);
261 } else {
262 d->update();
263 }
264 break;
265 case QEvent::Show:
266 d->update();
267 show();
268 break;
269 case QEvent::PaletteChange:
270 setPalette(d->widget->palette());
271 break;
272 case QEvent::ZOrderChange:
273 if (style()->styleHint(stylehint: QStyle::SH_FocusFrame_AboveWidget, opt: nullptr, widget: this))
274 raise();
275 else
276 stackUnder(d->widget);
277 break;
278 case QEvent::Destroy:
279 setWidget(nullptr);
280 break;
281 default:
282 break;
283 }
284 } else if (d->showFrameAboveWidget) {
285 // Handle changes in the parent widgets we are monitoring.
286 switch(e->type()) {
287 case QEvent::Move:
288 case QEvent::Resize:
289 d->updateSize();
290 break;
291 case QEvent::ZOrderChange:
292 raise();
293 break;
294 default:
295 break;
296 }
297 }
298 return false;
299}
300
301/*! \reimp */
302bool QFocusFrame::event(QEvent *e)
303{
304 Q_D(QFocusFrame);
305
306 switch (e->type()) {
307 case QEvent::Move:
308 case QEvent::Resize:
309 if (d->widget) {
310 // When we're tracking a widget, we don't allow anyone to move the focus frame around.
311 // We do our best with event filters to make it stay on top of the widget, so trying to
312 // move the frame somewhere else will be flaky at best. This can e.g happen for general
313 // purpose code, like QAbstractScrollView, that bulk-moves all children a certain distance.
314 // So we need to call updateSize() when that happens to ensure that the focus frame stays
315 // on top of the widget.
316 d->updateSize();
317 }
318 break;
319 default:
320 return QWidget::event(event: e);
321 }
322 return true;
323}
324
325QT_END_NAMESPACE
326
327#include "moc_qfocusframe.cpp"
328

source code of qtbase/src/widgets/widgets/qfocusframe.cpp