C++ FrameMetrics::GetPresShellResolution方法代码示例

void
APZCCallbackHelper::UpdateRootFrame(FrameMetrics& aMetrics)
{
  if (aMetrics.GetScrollId() == FrameMetrics::NULL_SCROLL_ID) {
    return;
  }
  nsIContent* content = nsLayoutUtils::FindContentFor(aMetrics.GetScrollId());
  if (!content) {
    return;
  }

  nsCOMPtr<nsIPresShell> shell = GetPresShell(content);
  if (!shell || aMetrics.GetPresShellId() != shell->GetPresShellId()) {
    return;
  }

  MOZ_ASSERT(aMetrics.GetUseDisplayPortMargins());

  if (gfxPrefs::APZAllowZooming()) {
    // If zooming is disabled then we don't really want to let APZ fiddle
    // with these things. In theory setting the resolution here should be a
    // no-op, but setting the SPCSPS is bad because it can cause a stale value
    // to be returned by window.innerWidth/innerHeight (see bug 1187792).

    float presShellResolution = nsLayoutUtils::GetResolution(shell);

    // If the pres shell resolution has changed on the content side side
    // the time this repaint request was fired, consider this request out of date
    // and drop it; setting a zoom based on the out-of-date resolution can have
    // the effect of getting us stuck with the stale resolution.
    if (presShellResolution != aMetrics.GetPresShellResolution()) {
      return;
    }

    // Set the scroll port size, which determines the scroll range. For example if
    // a 500-pixel document is shown in a 100-pixel frame, the scroll port length would
    // be 100, and gecko would limit the maximum scroll offset to 400 (so as to prevent
    // overscroll). Note that if the content here was zoomed to 2x, the document would
    // be 1000 pixels long but the frame would still be 100 pixels, and so the maximum
    // scroll range would be 900. Therefore this calculation depends on the zoom applied
    // to the content relative to the container.
    // Note that this needs to happen before scrolling the frame (in UpdateFrameCommon),
    // otherwise the scroll position may get clamped incorrectly.
    CSSSize scrollPort = aMetrics.CalculateCompositedSizeInCssPixels();
    nsLayoutUtils::SetScrollPositionClampingScrollPortSize(shell, scrollPort);

    // The pres shell resolution is updated by the the async zoom since the
    // last paint.
    presShellResolution = aMetrics.GetPresShellResolution()
                        * aMetrics.GetAsyncZoom().scale;
    nsLayoutUtils::SetResolutionAndScaleTo(shell, presShellResolution);
  }

  // Do this as late as possible since scrolling can flush layout. It also
  // adjusts the display port margins, so do it before we set those.
  ScrollFrame(content, aMetrics);

  SetDisplayPortMargins(shell, content, aMetrics);
}

void
APZCCallbackHelper::UpdateRootFrame(FrameMetrics& aMetrics)
{
  if (aMetrics.GetScrollId() == FrameMetrics::NULL_SCROLL_ID) {
    return;
  }
  nsIContent* content = nsLayoutUtils::FindContentFor(aMetrics.GetScrollId());
  if (!content) {
    return;
  }

  nsCOMPtr<nsIPresShell> shell = GetPresShell(content);
  if (!shell || aMetrics.GetPresShellId() != shell->GetPresShellId()) {
    return;
  }

  MOZ_ASSERT(aMetrics.GetUseDisplayPortMargins());

  if (gfxPrefs::APZAllowZooming()) {
    // If zooming is disabled then we don't really want to let APZ fiddle
    // with these things. In theory setting the resolution here should be a
    // no-op, but setting the SPCSPS is bad because it can cause a stale value
    // to be returned by window.innerWidth/innerHeight (see bug 1187792).

    float presShellResolution = shell->GetResolution();

    // If the pres shell resolution has changed on the content side side
    // the time this repaint request was fired, consider this request out of date
    // and drop it; setting a zoom based on the out-of-date resolution can have
    // the effect of getting us stuck with the stale resolution.
    if (presShellResolution != aMetrics.GetPresShellResolution()) {
      return;
    }

    // The pres shell resolution is updated by the the async zoom since the
    // last paint.
    presShellResolution = aMetrics.GetPresShellResolution()
                        * aMetrics.GetAsyncZoom().scale;
    shell->SetResolutionAndScaleTo(presShellResolution);
  }

  // Do this as late as possible since scrolling can flush layout. It also
  // adjusts the display port margins, so do it before we set those.
  ScrollFrame(content, aMetrics);

  MOZ_ASSERT(nsLayoutUtils::HasDisplayPort(content));
  SetDisplayPortMargins(shell, content, aMetrics);
  SetPaintRequestTime(content, aMetrics.GetPaintRequestTime());
}

void
APZCCallbackHelper::UpdateRootFrame(nsIDOMWindowUtils* aUtils,
                                    FrameMetrics& aMetrics)
{
  // Precondition checks
  MOZ_ASSERT(aUtils);
  MOZ_ASSERT(aMetrics.GetUseDisplayPortMargins());
  if (aMetrics.GetScrollId() == FrameMetrics::NULL_SCROLL_ID) {
    return;
  }

  // Set the scroll port size, which determines the scroll range. For example if
  // a 500-pixel document is shown in a 100-pixel frame, the scroll port length would
  // be 100, and gecko would limit the maximum scroll offset to 400 (so as to prevent
  // overscroll). Note that if the content here was zoomed to 2x, the document would
  // be 1000 pixels long but the frame would still be 100 pixels, and so the maximum
  // scroll range would be 900. Therefore this calculation depends on the zoom applied
  // to the content relative to the container.
  // Note that this needs to happen before scrolling the frame (in UpdateFrameCommon),
  // otherwise the scroll position may get clamped incorrectly.
  CSSSize scrollPort = aMetrics.CalculateCompositedSizeInCssPixels();
  aUtils->SetScrollPositionClampingScrollPortSize(scrollPort.width, scrollPort.height);

  nsIContent* content = nsLayoutUtils::FindContentFor(aMetrics.GetScrollId());
  ScrollFrame(content, aMetrics);

  // The pres shell resolution is updated by the the async zoom since the
  // last paint.
  float presShellResolution = aMetrics.GetPresShellResolution()
                            * aMetrics.GetAsyncZoom().scale;
  aUtils->SetResolutionAndScaleTo(presShellResolution, presShellResolution);

  SetDisplayPortMargins(aUtils, content, aMetrics);
}

void
APZCCallbackHelper::UpdateRootFrame(nsIPresShell* aPresShell,
                                    FrameMetrics& aMetrics)
{
  // Precondition checks
  MOZ_ASSERT(aPresShell);
  MOZ_ASSERT(aMetrics.GetUseDisplayPortMargins());
  if (aMetrics.GetScrollId() == FrameMetrics::NULL_SCROLL_ID) {
    return;
  }

  float presShellResolution = nsLayoutUtils::GetResolution(aPresShell);

  // If the pres shell resolution has changed on the content side side
  // the time this repaint request was fired, consider this request out of date
  // and drop it; setting a zoom based on the out-of-date resolution can have
  // the effect of getting us stuck with the stale resolution.
  if (presShellResolution != aMetrics.GetPresShellResolution()) {
    return;
  }

  // Set the scroll port size, which determines the scroll range. For example if
  // a 500-pixel document is shown in a 100-pixel frame, the scroll port length would
  // be 100, and gecko would limit the maximum scroll offset to 400 (so as to prevent
  // overscroll). Note that if the content here was zoomed to 2x, the document would
  // be 1000 pixels long but the frame would still be 100 pixels, and so the maximum
  // scroll range would be 900. Therefore this calculation depends on the zoom applied
  // to the content relative to the container.
  // Note that this needs to happen before scrolling the frame (in UpdateFrameCommon),
  // otherwise the scroll position may get clamped incorrectly.
  CSSSize scrollPort = aMetrics.CalculateCompositedSizeInCssPixels();
  nsLayoutUtils::SetScrollPositionClampingScrollPortSize(aPresShell, scrollPort);

  // The pres shell resolution is updated by the the async zoom since the
  // last paint.
  presShellResolution = aMetrics.GetPresShellResolution()
                      * aMetrics.GetAsyncZoom().scale;
  nsLayoutUtils::SetResolutionAndScaleTo(aPresShell, presShellResolution);

  // Do this as late as possible since scrolling can flush layout. It also
  // adjusts the display port margins, so do it before we set those.
  nsIContent* content = nsLayoutUtils::FindContentFor(aMetrics.GetScrollId());
  ScrollFrame(content, aMetrics);

  SetDisplayPortMargins(aPresShell, content, aMetrics);
}

void
AppendToString(std::stringstream& aStream, const FrameMetrics& m,
               const char* pfx, const char* sfx, bool detailed)
{
  aStream << pfx;
  AppendToString(aStream, m.GetCompositionBounds(), "{ [cb=");
  AppendToString(aStream, m.GetScrollableRect(), "] [sr=");
  AppendToString(aStream, m.GetScrollOffset(), "] [s=");
  if (m.GetDoSmoothScroll()) {
    AppendToString(aStream, m.GetSmoothScrollOffset(), "] [ss=");
  }
  AppendToString(aStream, m.GetDisplayPort(), "] [dp=");
  AppendToString(aStream, m.GetCriticalDisplayPort(), "] [cdp=");
  AppendToString(aStream, m.GetBackgroundColor(), "] [color=");
  if (!detailed) {
    AppendToString(aStream, m.GetScrollId(), "] [scrollId=");
    if (m.GetScrollParentId() != FrameMetrics::NULL_SCROLL_ID) {
      AppendToString(aStream, m.GetScrollParentId(), "] [scrollParent=");
    }
    if (m.IsRootContent()) {
      aStream << "] [rcd";
    }
    if (m.HasClipRect()) {
      AppendToString(aStream, m.ClipRect(), "] [clip=");
    }
    AppendToString(aStream, m.GetZoom(), "] [z=", "] }");
  } else {
    AppendToString(aStream, m.GetDisplayPortMargins(), " [dpm=");
    aStream << nsPrintfCString("] um=%d", m.GetUseDisplayPortMargins()).get();
    AppendToString(aStream, m.GetRootCompositionSize(), "] [rcs=");
    AppendToString(aStream, m.GetViewport(), "] [v=");
    aStream << nsPrintfCString("] [z=(ld=%.3f r=%.3f",
            m.GetDevPixelsPerCSSPixel().scale,
            m.GetPresShellResolution()).get();
    AppendToString(aStream, m.GetCumulativeResolution(), " cr=");
    AppendToString(aStream, m.GetZoom(), " z=");
    AppendToString(aStream, m.GetExtraResolution(), " er=");
    aStream << nsPrintfCString(")] [u=(%d %d %lu)",
            m.GetScrollOffsetUpdated(), m.GetDoSmoothScroll(),
            m.GetScrollGeneration()).get();
    AppendToString(aStream, m.GetScrollParentId(), "] [p=");
    aStream << nsPrintfCString("] [i=(%ld %lld %d)] }",
            m.GetPresShellId(), m.GetScrollId(), m.IsRootContent()).get();
  }
  aStream << sfx;
}

void
APZCCallbackHelper::UpdateRootFrame(nsIDOMWindowUtils* aUtils,
                                    FrameMetrics& aMetrics)
{
    // Precondition checks
    MOZ_ASSERT(aUtils);
    MOZ_ASSERT(aMetrics.GetUseDisplayPortMargins());
    if (aMetrics.GetScrollId() == FrameMetrics::NULL_SCROLL_ID) {
        return;
    }

    // Set the scroll port size, which determines the scroll range. For example if
    // a 500-pixel document is shown in a 100-pixel frame, the scroll port length would
    // be 100, and gecko would limit the maximum scroll offset to 400 (so as to prevent
    // overscroll). Note that if the content here was zoomed to 2x, the document would
    // be 1000 pixels long but the frame would still be 100 pixels, and so the maximum
    // scroll range would be 900. Therefore this calculation depends on the zoom applied
    // to the content relative to the container.
    CSSSize scrollPort = aMetrics.CalculateCompositedSizeInCssPixels();
    aUtils->SetScrollPositionClampingScrollPortSize(scrollPort.width, scrollPort.height);

    // Scroll the window to the desired spot
    nsIScrollableFrame* sf = nsLayoutUtils::FindScrollableFrameFor(aMetrics.GetScrollId());
    bool scrollUpdated = false;
    CSSPoint actualScrollOffset = ScrollFrameTo(sf, aMetrics.GetScrollOffset(), scrollUpdated);

    if (scrollUpdated) {
        // Correct the display port due to the difference between mScrollOffset and the
        // actual scroll offset.
        AdjustDisplayPortForScrollDelta(aMetrics, actualScrollOffset);
    } else {
        // For whatever reason we couldn't update the scroll offset on the scroll frame,
        // which means the data APZ used for its displayport calculation is stale. Fall
        // back to a sane default behaviour. Note that we don't tile-align the recentered
        // displayport because tile-alignment depends on the scroll position, and the
        // scroll position here is out of our control. See bug 966507 comment 21 for a
        // more detailed explanation.
        RecenterDisplayPort(aMetrics);
    }

    aMetrics.SetScrollOffset(actualScrollOffset);

    // The pres shell resolution is updated by the the async zoom since the
    // last paint.
    float presShellResolution = aMetrics.GetPresShellResolution()
                              * aMetrics.GetAsyncZoom().scale;
    aUtils->SetResolutionAndScaleTo(presShellResolution, presShellResolution);

    // Finally, we set the displayport.
    nsCOMPtr<nsIContent> content = nsLayoutUtils::FindContentFor(aMetrics.GetScrollId());
    if (!content) {
        return;
    }
    nsCOMPtr<nsIDOMElement> element = do_QueryInterface(content);
    if (!element) {
        return;
    }

    ScreenMargin margins = aMetrics.GetDisplayPortMargins();
    aUtils->SetDisplayPortMarginsForElement(margins.left,
                                            margins.top,
                                            margins.right,
                                            margins.bottom,
                                            element, 0);
    CSSRect baseCSS = aMetrics.CalculateCompositedRectInCssPixels();
    nsRect base(0, 0,
                baseCSS.width * nsPresContext::AppUnitsPerCSSPixel(),
                baseCSS.height * nsPresContext::AppUnitsPerCSSPixel());
    nsLayoutUtils::SetDisplayPortBaseIfNotSet(content, base);
}