1/*
2 * Copyright (C) 2004, 2008, 2009, 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "core/editing/Caret.h"
28
29#include "core/dom/Document.h"
30#include "core/editing/htmlediting.h"
31#include "core/page/Frame.h"
32#include "core/page/Settings.h"
33#include "core/rendering/RenderBlock.h"
34#include "core/rendering/RenderView.h"
35
36namespace WebCore {
37
38static inline LayoutUnit NoXPosForVerticalArrowNavigation()
39{
40    return LayoutUnit::min();
41}
42
43CaretBase::CaretBase(CaretVisibility visibility)
44    : m_caretRectNeedsUpdate(true)
45    , m_caretVisibility(visibility)
46{
47}
48
49DragCaretController::DragCaretController()
50    : CaretBase(Visible)
51{
52}
53
54PassOwnPtr<DragCaretController> DragCaretController::create()
55{
56    return adoptPtr(new DragCaretController);
57}
58
59bool DragCaretController::isContentRichlyEditable() const
60{
61    return isRichlyEditablePosition(m_position.deepEquivalent());
62}
63
64void DragCaretController::setCaretPosition(const VisiblePosition& position)
65{
66    if (Node* node = m_position.deepEquivalent().deprecatedNode())
67        invalidateCaretRect(node);
68    m_position = position;
69    setCaretRectNeedsUpdate();
70    Document* document = 0;
71    if (Node* node = m_position.deepEquivalent().deprecatedNode()) {
72        invalidateCaretRect(node);
73        document = node->document();
74    }
75    if (m_position.isNull() || m_position.isOrphan())
76        clearCaretRect();
77    else
78        updateCaretRect(document, m_position);
79}
80
81static bool removingNodeRemovesPosition(Node* node, const Position& position)
82{
83    if (!position.anchorNode())
84        return false;
85
86    if (position.anchorNode() == node)
87        return true;
88
89    if (!node->isElementNode())
90        return false;
91
92    Element* element = toElement(node);
93    return element->containsIncludingShadowDOM(position.anchorNode());
94}
95
96static void clearRenderViewSelection(const Position& position)
97{
98    RefPtr<Document> document = position.anchorNode()->document();
99    document->updateStyleIfNeeded();
100    if (RenderView* view = document->renderView())
101        view->clearSelection();
102}
103
104void DragCaretController::nodeWillBeRemoved(Node* node)
105{
106    if (!hasCaret() || (node && !node->inDocument()))
107        return;
108
109    if (!removingNodeRemovesPosition(node, m_position.deepEquivalent()))
110        return;
111
112    clearRenderViewSelection(m_position.deepEquivalent());
113    clear();
114}
115
116void CaretBase::clearCaretRect()
117{
118    m_caretLocalRect = LayoutRect();
119}
120
121static inline bool caretRendersInsideNode(Node* node)
122{
123    return node && !isTableElement(node) && !editingIgnoresContent(node);
124}
125
126RenderObject* CaretBase::caretRenderer(Node* node)
127{
128    if (!node)
129        return 0;
130
131    RenderObject* renderer = node->renderer();
132    if (!renderer)
133        return 0;
134
135    // if caretNode is a block and caret is inside it then caret should be painted by that block
136    bool paintedByBlock = renderer->isBlockFlow() && caretRendersInsideNode(node);
137    return paintedByBlock ? renderer : renderer->containingBlock();
138}
139
140bool CaretBase::updateCaretRect(Document* document, const VisiblePosition& caretPosition)
141{
142    document->updateStyleIfNeeded();
143    m_caretLocalRect = LayoutRect();
144
145    m_caretRectNeedsUpdate = false;
146
147    if (caretPosition.isNull())
148        return false;
149
150    ASSERT(caretPosition.deepEquivalent().deprecatedNode()->renderer());
151
152    // First compute a rect local to the renderer at the selection start.
153    RenderObject* renderer;
154    LayoutRect localRect = caretPosition.localCaretRect(renderer);
155
156    // Get the renderer that will be responsible for painting the caret
157    // (which is either the renderer we just found, or one of its containers).
158    RenderObject* caretPainter = caretRenderer(caretPosition.deepEquivalent().deprecatedNode());
159
160    // Compute an offset between the renderer and the caretPainter.
161    bool unrooted = false;
162    while (renderer != caretPainter) {
163        RenderObject* containerObject = renderer->container();
164        if (!containerObject) {
165            unrooted = true;
166            break;
167        }
168        localRect.move(renderer->offsetFromContainer(containerObject, localRect.location()));
169        renderer = containerObject;
170    }
171
172    if (!unrooted)
173        m_caretLocalRect = localRect;
174
175    return true;
176}
177
178RenderObject* DragCaretController::caretRenderer() const
179{
180    return CaretBase::caretRenderer(m_position.deepEquivalent().deprecatedNode());
181}
182
183IntRect CaretBase::absoluteBoundsForLocalRect(Node* node, const LayoutRect& rect) const
184{
185    RenderObject* caretPainter = caretRenderer(node);
186    if (!caretPainter)
187        return IntRect();
188
189    LayoutRect localRect(rect);
190    if (caretPainter->isBox())
191        toRenderBox(caretPainter)->flipForWritingMode(localRect);
192    return caretPainter->localToAbsoluteQuad(FloatRect(localRect)).enclosingBoundingBox();
193}
194
195void CaretBase::repaintCaretForLocalRect(Node* node, const LayoutRect& rect)
196{
197    RenderObject* caretPainter = caretRenderer(node);
198    if (!caretPainter)
199        return;
200
201    // FIXME: Need to over-paint 1 pixel to workaround some rounding problems.
202    // https://bugs.webkit.org/show_bug.cgi?id=108283
203    LayoutRect inflatedRect = rect;
204    inflatedRect.inflate(1);
205
206    caretPainter->repaintRectangle(inflatedRect);
207}
208
209bool CaretBase::shouldRepaintCaret(const RenderView* view, bool isContentEditable) const
210{
211    ASSERT(view);
212    Frame* frame = view->frameView() ? view->frameView()->frame() : 0; // The frame where the selection started.
213    bool caretBrowsing = frame && frame->settings() && frame->settings()->caretBrowsingEnabled();
214    return (caretBrowsing || isContentEditable);
215}
216
217void CaretBase::invalidateCaretRect(Node* node, bool caretRectChanged)
218{
219    // EDIT FIXME: This is an unfortunate hack.
220    // Basically, we can't trust this layout position since we
221    // can't guarantee that the check to see if we are in unrendered
222    // content will work at this point. We may have to wait for
223    // a layout and re-render of the document to happen. So, resetting this
224    // flag will cause another caret layout to happen the first time
225    // that we try to paint the caret after this call. That one will work since
226    // it happens after the document has accounted for any editing
227    // changes which may have been done.
228    // And, we need to leave this layout here so the caret moves right
229    // away after clicking.
230    m_caretRectNeedsUpdate = true;
231
232    if (caretRectChanged)
233        return;
234
235    if (RenderView* view = node->document()->renderView()) {
236        if (shouldRepaintCaret(view, node->isContentEditable(Node::UserSelectAllIsAlwaysNonEditable)))
237            repaintCaretForLocalRect(node, localCaretRectWithoutUpdate());
238    }
239}
240
241void CaretBase::paintCaret(Node* node, GraphicsContext* context, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
242{
243    if (m_caretVisibility == Hidden)
244        return;
245
246    LayoutRect drawingRect = localCaretRectWithoutUpdate();
247    RenderObject* renderer = caretRenderer(node);
248    if (renderer && renderer->isBox())
249        toRenderBox(renderer)->flipForWritingMode(drawingRect);
250    drawingRect.moveBy(roundedIntPoint(paintOffset));
251    LayoutRect caret = intersection(drawingRect, clipRect);
252    if (caret.isEmpty())
253        return;
254
255    Color caretColor = Color::black;
256
257    Element* element;
258    if (node->isElementNode())
259        element = toElement(node);
260    else
261        element = node->parentElement();
262
263    if (element && element->renderer())
264        caretColor = element->renderer()->resolveColor(CSSPropertyColor);
265
266    context->fillRect(caret, caretColor);
267}
268
269void DragCaretController::paintDragCaret(Frame* frame, GraphicsContext* p, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
270{
271    if (m_position.deepEquivalent().deprecatedNode()->document()->frame() == frame)
272        paintCaret(m_position.deepEquivalent().deprecatedNode(), p, paintOffset, clipRect);
273}
274
275}
276