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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
#include "nsHTMLButtonControlFrame.h"
#include "mozilla/PresShell.h"
#include "nsContainerFrame.h"
#include "nsIFormControlFrame.h"
#include "nsIFrameInlines.h"
#include "nsPresContext.h"
#include "nsGkAtoms.h"
#include "nsButtonFrameRenderer.h"
#include "nsCSSAnonBoxes.h"
#include "nsNameSpaceManager.h"
#include "nsDisplayList.h"
#include <algorithm>
using namespace mozilla;
nsContainerFrame* NS_NewHTMLButtonControlFrame(PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsHTMLButtonControlFrame(aStyle, aPresShell->GetPresContext());
nsHTMLButtonControlFrame::nsHTMLButtonControlFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext,
nsIFrame::ClassID aID)
: nsContainerFrame(aStyle, aPresContext, aID) {}
nsHTMLButtonControlFrame::~nsHTMLButtonControlFrame() = default;
void nsHTMLButtonControlFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
mRenderer.SetFrame(this, PresContext());
a11y::AccType nsHTMLButtonControlFrame::AccessibleType() {
return a11y::eHTMLButtonType;
void nsHTMLButtonControlFrame::SetFocus(bool aOn, bool aRepaint) {}
nsresult nsHTMLButtonControlFrame::HandleEvent(nsPresContext* aPresContext,
WidgetGUIEvent* aEvent,
nsEventStatus* aEventStatus) {
// if disabled do nothing
if (mRenderer.isDisabled()) {
return NS_OK;
// mouse clicks are handled by content
// we don't want our children to get any events. So just pass it to frame.
return nsIFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
bool nsHTMLButtonControlFrame::ShouldClipPaintingToBorderBox() {
return IsInput() || StyleDisplay()->mOverflowX != StyleOverflow::Visible;
void nsHTMLButtonControlFrame::BuildDisplayList(
nsDisplayListBuilder* aBuilder, const nsDisplayListSet& aLists) {
nsDisplayList onTop(aBuilder);
if (IsVisibleForPainting()) {
// Clip the button itself to its border area for event hit testing.
Maybe<DisplayListClipState::AutoSaveRestore> eventClipState;
if (aBuilder->IsForEventDelivery()) {
nsRect rect(aBuilder->ToReferenceFrame(this), GetSize());
nscoord radii[8];
bool hasRadii = GetBorderRadii(radii);
rect, hasRadii ? radii : nullptr);
mRenderer.DisplayButton(aBuilder, aLists.BorderBackground(), &onTop);
nsDisplayListCollection set(aBuilder);
DisplayListClipState::AutoSaveRestore clipState(aBuilder);
if (ShouldClipPaintingToBorderBox()) {
nsMargin border = StyleBorder()->GetComputedBorder();
nsRect rect(aBuilder->ToReferenceFrame(this), GetSize());
nscoord radii[8];
bool hasRadii = GetPaddingBoxBorderRadii(radii);
hasRadii ? radii : nullptr);
BuildDisplayListForChild(aBuilder, mFrames.FirstChild(), set,
// Put the foreground outline and focus rects on top of the children
DisplayOutline(aBuilder, aLists);
// to draw border when selected in editor
DisplaySelectionOverlay(aBuilder, aLists.Content());
nscoord nsHTMLButtonControlFrame::GetMinISize(gfxContext* aRenderingContext) {
nscoord result;
if (Maybe<nscoord> containISize = ContainIntrinsicISize()) {
result = *containISize;
} else {
nsIFrame* kid = mFrames.FirstChild();
result = nsLayoutUtils::IntrinsicForContainer(aRenderingContext, kid,
return result;
nscoord nsHTMLButtonControlFrame::GetPrefISize(gfxContext* aRenderingContext) {
nscoord result;
if (Maybe<nscoord> containISize = ContainIntrinsicISize()) {
result = *containISize;
} else {
nsIFrame* kid = mFrames.FirstChild();
result = nsLayoutUtils::IntrinsicForContainer(
aRenderingContext, kid, IntrinsicISizeType::PrefISize);
return result;
void nsHTMLButtonControlFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) {
DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
// Reflow the child
nsIFrame* firstKid = mFrames.FirstChild();
MOZ_ASSERT(firstKid, "Button should have a child frame for its contents");
"Button should have exactly one child frame");
firstKid->Style()->GetPseudoType() == PseudoStyleType::buttonContent,
"Button's child frame has unexpected pseudo type!");
// XXXbz Eventually we may want to check-and-bail if
// !aReflowInput.ShouldReflowAllKids() &&
// !firstKid->IsSubtreeDirty().
// We'd need to cache our ascent for that, of course.
// Reflow the contents of the button.
// (This populates our aDesiredSize, too.)
ReflowButtonContents(aPresContext, aDesiredSize, aReflowInput, firstKid);
if (!ShouldClipPaintingToBorderBox()) {
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, firstKid);
// else, we ignore child overflow -- anything that overflows beyond our
// own border-box will get clipped when painting.
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize, aReflowInput,
// We're always complete and we don't support overflow containers
// so we shouldn't have a next-in-flow ever.
void nsHTMLButtonControlFrame::ReflowButtonContents(
nsPresContext* aPresContext, ReflowOutput& aButtonDesiredSize,
const ReflowInput& aButtonReflowInput, nsIFrame* aFirstKid) {
WritingMode wm = GetWritingMode();
LogicalSize availSize = aButtonReflowInput.ComputedSize(wm);
// shorthand for a value we need to use in a bunch of places
const LogicalMargin& clbp =
LogicalPoint childPos(wm);
childPos.I(wm) = clbp.IStart(wm);
availSize.ISize(wm) = std::max(availSize.ISize(wm), 0);
ReflowInput contentsReflowInput(aPresContext, aButtonReflowInput, aFirstKid,
nsReflowStatus contentsReflowStatus;
ReflowOutput contentsDesiredSize(aButtonReflowInput);
childPos.B(wm) = 0; // This will be set properly later, after reflowing the
// child to determine its size.
const LayoutFrameType frameType = aFirstKid->Type();
if (frameType == LayoutFrameType::FlexContainer ||
frameType == LayoutFrameType::GridContainer) {
contentsReflowInput.ComputedBSize() = aButtonReflowInput.ComputedBSize();
contentsReflowInput.ComputedMinBSize() =
contentsReflowInput.ComputedMaxBSize() =
// We just pass a dummy containerSize here, as the child will be
// repositioned later by FinishReflowChild.
nsSize dummyContainerSize;
ReflowChild(aFirstKid, aPresContext, contentsDesiredSize, contentsReflowInput,
wm, childPos, dummyContainerSize, ReflowChildFlags::Default,
"We gave button-contents frame unconstrained available height, "
"so it should be complete");
// Compute the button's content-box size:
LogicalSize buttonContentBox(wm);
if (aButtonReflowInput.ComputedBSize() != NS_UNCONSTRAINEDSIZE) {
// Button has a fixed block-size -- that's its content-box bSize.
buttonContentBox.BSize(wm) = aButtonReflowInput.ComputedBSize();
} else {
// Button is intrinsically sized -- it should shrinkwrap the
// button-contents' bSize. But if it has size containment in block axis,
// ignore the contents and use contain-intrinsic-block-size.
nscoord bSize = aButtonReflowInput.mFrame->ContainIntrinsicBSize().valueOr(
// Make sure we obey min/max-bSize in the case when we're doing intrinsic
// sizing (we get it for free when we have a non-intrinsic
// aButtonReflowInput.ComputedBSize()). Note that we do this before
// adjusting for borderpadding, since mComputedMaxBSize and
// mComputedMinBSize are content bSizes.
buttonContentBox.BSize(wm) =
NS_CSS_MINMAX(bSize, aButtonReflowInput.ComputedMinBSize(),
if (aButtonReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE) {
buttonContentBox.ISize(wm) = aButtonReflowInput.ComputedISize();
} else {
nscoord iSize = aButtonReflowInput.mFrame->ContainIntrinsicISize().valueOr(
buttonContentBox.ISize(wm) =
NS_CSS_MINMAX(iSize, aButtonReflowInput.ComputedMinISize(),
// Center child in the block-direction in the button
// (technically, inside of the button's focus-padding area)
nscoord extraSpace =
buttonContentBox.BSize(wm) - contentsDesiredSize.BSize(wm);
childPos.B(wm) = std::max(0, extraSpace / 2);
// Adjust childPos.B() to be in terms of the button's frame-rect:
childPos.B(wm) += clbp.BStart(wm);
nsSize containerSize = (buttonContentBox + clbp.Size(wm)).GetPhysicalSize(wm);
// Place the child
FinishReflowChild(aFirstKid, aPresContext, contentsDesiredSize,
&contentsReflowInput, wm, childPos, containerSize,
// Make sure we have a useful 'ascent' value for the child
if (contentsDesiredSize.BlockStartAscent() ==
ReflowOutput::ASK_FOR_BASELINE) {
WritingMode wm = aButtonReflowInput.GetWritingMode();
// OK, we're done with the child frame.
// Use what we learned to populate the button frame's reflow metrics.
// * Button's height & width are content-box size + border-box contribution:
LogicalSize(wm, aButtonReflowInput.ComputedISize() + clbp.IStartEnd(wm),
buttonContentBox.BSize(wm) + clbp.BStartEnd(wm)));
// * Button's ascent is its child's ascent, plus the child's block-offset
// within our frame... unless it's orthogonal, in which case we'll use the
// contents inline-size as an approximation for now.
// XXX is there a better strategy? should we include border-padding?
if (!aButtonReflowInput.mStyleDisplay->IsContainLayout()) {
if (aButtonDesiredSize.GetWritingMode().IsOrthogonalTo(wm)) {
} else {
contentsDesiredSize.BlockStartAscent() + childPos.B(wm));
} // else: we're layout-contained, and so we have no baseline.
bool nsHTMLButtonControlFrame::GetVerticalAlignBaseline(
mozilla::WritingMode aWM, nscoord* aBaseline) const {
nsIFrame* inner = mFrames.FirstChild();
if (MOZ_UNLIKELY(inner->GetWritingMode().IsOrthogonalTo(aWM))) {
return false;
if (!inner->GetVerticalAlignBaseline(aWM, aBaseline)) {
// <input type=color> has an empty block frame as inner frame
*aBaseline = inner->SynthesizeBaselineBOffsetFromBorderBox(
aWM, BaselineSharingGroup::First);
nscoord innerBStart = inner->BStart(aWM, GetSize());
*aBaseline += innerBStart;
return true;
bool nsHTMLButtonControlFrame::GetNaturalBaselineBOffset(
mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup,
nscoord* aBaseline) const {
if (StyleDisplay()->IsContainLayout()) {
return false;
nsIFrame* inner = mFrames.FirstChild();
if (MOZ_UNLIKELY(inner->GetWritingMode().IsOrthogonalTo(aWM))) {
return false;
if (!inner->GetNaturalBaselineBOffset(aWM, aBaselineGroup, aBaseline)) {
// <input type=color> has an empty block frame as inner frame
*aBaseline =
inner->SynthesizeBaselineBOffsetFromBorderBox(aWM, aBaselineGroup);
nscoord innerBStart = inner->BStart(aWM, GetSize());
if (aBaselineGroup == BaselineSharingGroup::First) {
*aBaseline += innerBStart;
} else {
*aBaseline += BSize(aWM) - (innerBStart + inner->BSize(aWM));
return true;
nsresult nsHTMLButtonControlFrame::SetFormProperty(nsAtom* aName,
const nsAString& aValue) {
if (nsGkAtoms::value == aName) {
return mContent->AsElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::value,
aValue, true);
return NS_OK;
ComputedStyle* nsHTMLButtonControlFrame::GetAdditionalComputedStyle(
int32_t aIndex) const {
return mRenderer.GetComputedStyle(aIndex);
void nsHTMLButtonControlFrame::SetAdditionalComputedStyle(
int32_t aIndex, ComputedStyle* aComputedStyle) {
mRenderer.SetComputedStyle(aIndex, aComputedStyle);
void nsHTMLButtonControlFrame::AppendDirectlyOwnedAnonBoxes(
nsTArray<OwnedAnonBox>& aResult) {
MOZ_ASSERT(mFrames.FirstChild(), "Must have our button-content anon box");
"Must only have our button-content anon box");
#ifdef DEBUG
void nsHTMLButtonControlFrame::AppendFrames(ChildListID aListID,
nsFrameList& aFrameList) {
MOZ_CRASH("unsupported operation");
void nsHTMLButtonControlFrame::InsertFrames(
ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine, nsFrameList& aFrameList) {
MOZ_CRASH("unsupported operation");
void nsHTMLButtonControlFrame::RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame) {
MOZ_CRASH("unsupported operation");