[Mac] Implement the system dictionary popup by implementing NSTextInput methods.

third_party/WebKit/Source/WebKit/chromium/src/mac/WebTextHelper.mm

+/*

[jam, 2011/01/21 18:51:07]

nit: usually we have the interface in the public directory, like what you have. 
there are then two corresponding Impl.h/cpp/mm files in the src directory.

[Robert Sesek, 2011/01/21 23:40:07]

Ok. I won't do that now because it's easier for this to be contained in one
place while developing, but I'll do that before upstreaming.

+ * Copyright (C) 2011 Google Inc. All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WebFrameImpl.h"
+#include "WebTextHelper.h"
+
+#include "ColorMac.h"
+#include "Document.h"
+#include "Element.h"
+#include "FocusController.h"
+#include "Frame.h"
+#include "FrameView.h"
+#include "HitTestResult.h"
+#include "HTMLElement.h"
+#include "Node.h"
+#include "Range.h"
+#include "TextIterator.h"
+#include "WebRect.h"
+#include "WebString.h"
+
+#import <Cocoa/Cocoa.h>
+
+using namespace WebCore;
+
+namespace WebKit {
+
+// This is the internal implementation of WebTextHelper that can return WebCore
+// types.
+class WebTextHelperImpl {
+public:
+    explicit WebTextHelperImpl(WebFrame* frame) : m_frame(frame) {}
+
+    IntRect firstRectForWkRange(Range* range);
+
+    Range* characterRangeAtPoint(const IntPoint point);
+
+    void getLocationAndLengthFromRange(Range* range, NSUInteger& location, NSUInteger& length);
+
+    Element* rangeScope();
+
+    WebFrameImpl* webframeimpl();
+
+protected:
+    WebFrame* m_frame;
+};
+
+IntRect WebTextHelperImpl::firstRectForWkRange(Range* range)
+{
+    return webframeimpl()->frame()->editor()->firstRectForRange(range);
+}
+
+// This function is copied from /WebKit2/WebPage/mac/WebPageMac.mm.
+Range* WebTextHelperImpl::characterRangeAtPoint(const IntPoint point)
+{
+    Frame* frame(webframeimpl()->frame());
+
+    VisiblePosition position = frame->visiblePositionForPoint(point);
+    if (position.isNull())
+        return NULL;
+
+    VisiblePosition previous = position.previous();
+    if (previous.isNotNull()) {
+        Range* previousCharacterRange = makeRange(previous, position).get();
+        IntRect rect = firstRectForWkRange(previousCharacterRange);
+        if (rect.contains(point))
+            return previousCharacterRange;
+    }
+
+    VisiblePosition next = position.next();
+    if (next.isNotNull()) {
+        Range* nextCharacterRange = makeRange(position, next).get();
+        IntRect rect = firstRectForWkRange(nextCharacterRange);
+        if (rect.contains(point))
+            return nextCharacterRange;
+    }
+
+    return NULL;
+}
+
+// This function is copied from /WebKit2/WebPage/WebPage.cpp.
+void WebTextHelperImpl::getLocationAndLengthFromRange(Range* range, NSUInteger& location, NSUInteger& length)
+{
+    location = notFound;
+    length = 0;
+
+    if (!range || !range->startContainer())
+        return;
+
+    Element* selectionRoot = range->ownerDocument()->frame()->selection()->rootEditableElement();
+    Element* scope = selectionRoot ? selectionRoot : range->ownerDocument()->documentElement();
+
+    // Mouse events may cause TSM to attempt to create an NSRange for a portion of the view
+    // that is not inside the current editable region.  These checks ensure we don't produce
+    // potentially invalid data when responding to such requests.
+    if (range->startContainer() != scope && !range->startContainer()->isDescendantOf(scope))
+        return;
+    if (range->endContainer() != scope && !range->endContainer()->isDescendantOf(scope))
+        return;
+
+    RefPtr<Range> testRange = Range::create(scope->document(), scope, 0, range->startContainer(), range->startOffset());
+    ASSERT(testRange->startContainer() == scope);
+    location = TextIterator::rangeLength(testRange.get());
+    
+    ExceptionCode ec;
+    testRange->setEnd(range->endContainer(), range->endOffset(), ec);
+    ASSERT(testRange->startContainer() == scope);
+    length = TextIterator::rangeLength(testRange.get()) - location;
+}
+
+Element* WebTextHelperImpl::rangeScope()
+{
+    Frame* frame(webframeimpl()->frame());
+    Element* selectionRoot(frame->selection()->rootEditableElement());
+    return selectionRoot ? selectionRoot : frame->document()->documentElement();
+}
+
+WebFrameImpl* WebTextHelperImpl::webframeimpl()
+{
+    return static_cast<WebFrameImpl*>(m_frame);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+WebTextHelper::WebTextHelper(WebFrame* frame)
+    : m_private(new WebTextHelperImpl(frame))
+{
+}
+
+WebTextHelper::~WebTextHelper()
+{
+    m_private.reset(0);
+}
+
+uint WebTextHelper::characterIndexForPoint(int x, int y)
+{
+    Frame* frame(m_private->webframeimpl()->frame());
+    if (!frame)
+        return NSNotFound;
+
+    IntPoint scrollPosition(frame->view()->scrollPosition());
+    IntPoint point(x + scrollPosition.x(), y + scrollPosition.y());
+    HitTestResult result = frame->eventHandler()->hitTestResultAtPoint(point, false);
+    frame = result.innerNonSharedNode() ? result.innerNonSharedNode()->document()->frame() : frame->page()->focusController()->focusedOrMainFrame();
+
+    Range* range(m_private->characterRangeAtPoint(result.point()));
+    if (!range)
+        return NSNotFound;
+
+    NSRange nsRange = { 0 };
+    m_private->getLocationAndLengthFromRange(range, nsRange.location, nsRange.length);
+
+    return nsRange.location;
+}
+
+WebKit::WebRect WebTextHelper::firstRectForRange(uint location, uint length)
+{
+    Frame* frame(m_private->webframeimpl()->frame());
+    if (frame->view()->needsLayout())
+        frame->view()->layout();
+
+    RefPtr<Range> range(TextIterator::rangeFromLocationAndLength(m_private->rangeScope(), location, length));

[James Su, 2011/01/21 00:02:47]

range could be NULL if the given location is out of the content range (eg. when
there is no content at all). But in this case, we still need to return the caret
rect.

[Robert Sesek, 2011/01/21 23:40:07]

Taken care of the NULL dereference. But I don't think we should return an
arbitrary rect (the caret rect) if it's not found. We should probably handle
that in render_view instead.

+
+    WebKit::WebRect rect(m_private->firstRectForWkRange(range.get()));
+    IntPoint scrollPosition(frame->view()->scrollPosition());
+    rect.x += scrollPosition.x();
+    rect.y -= scrollPosition.y();
+    return rect;
+}
+
+// This function is copied from /WebKit/mac/Misc/WebNSAttributedStringExtras.mm.
+WebKit::WebString WebTextHelper::substringInRange(uint location, uint length)
+{
+    Frame* frame(m_private->webframeimpl()->frame());
+    if (frame->view()->needsLayout())
+        frame->view()->layout();
+
+    RefPtr<Range> range(TextIterator::rangeFromLocationAndLength(m_private->rangeScope(), location, length));

[James Su, 2011/01/21 00:02:47]

range could be NULL.

[Robert Sesek, 2011/01/21 23:40:07]

Done.

+
+    NSMutableAttributedString* string = [[NSMutableAttributedString alloc] init];
+    NSMutableDictionary* attrs = [NSMutableDictionary dictionary];
+
+    unsigned position = 0;
+    for (TextIterator it(range.get(), TextIteratorEntersTextControls);
+         !it.atEnd() && [string length] < length; it.advance()) {
+        unsigned numCharacters = it.length();
+        if (!numCharacters)
+            continue;
+
+        ExceptionCode exception = 0;
+        Node* container = it.range()->startContainer(exception);
+        RenderObject* renderer = container->renderer();
+        ASSERT(renderer);
+        if (!renderer)
+            continue;
+
+        RenderStyle* style = renderer->style();
+        NSFont* font = style->font().primaryFont()->getNSFont();
+        // If the platform font can't be loaded, it's likely that the site is
+        // using a web font. For now, just use the default font instead.
+        // TODO(rsesek): Change the font activation flags to allow other processes
+        // to use the font.
+        if (!font)
+          font = [NSFont systemFontOfSize:style->font().size()];
+        [attrs setObject:font forKey:NSFontAttributeName];
+
+        if (style->visitedDependentColor(CSSPropertyColor).alpha())
+            [attrs setObject:nsColor(style->visitedDependentColor(CSSPropertyColor)) forKey:NSForegroundColorAttributeName];
+        else
+            [attrs removeObjectForKey:NSForegroundColorAttributeName];
+        if (style->visitedDependentColor(CSSPropertyBackgroundColor).alpha())
+            [attrs setObject:nsColor(style->visitedDependentColor(CSSPropertyBackgroundColor)) forKey:NSBackgroundColorAttributeName];
+        else
+            [attrs removeObjectForKey:NSBackgroundColorAttributeName];
+
+        NSString* substring =
+            [[[NSString alloc] initWithCharactersNoCopy:const_cast<UChar*>(it.characters())
+                                                 length:it.length()
+                                           freeWhenDone:NO] autorelease];
+        [string replaceCharactersInRange:NSMakeRange(position, 0)
+                              withString:substring];
+        [string setAttributes:attrs range:NSMakeRange(position, numCharacters)];
+        position += numCharacters;
+    }
+    NSData* archivedData([NSArchiver archivedDataWithRootObject:string]);
+    return WebKit::WebString(static_cast<const WebUChar*>([archivedData bytes]),
+        [archivedData length]);
+}
+
+} // namespace WebKit