/* -*- 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 http://mozilla.org/MPL/2.0/. */
/* A namespace class for static muti-column utilities. */
#include "mozilla/ColumnUtils.h"
#include <algorithm>
#include "nsContainerFrame.h"
#include "nsLayoutUtils.h"
namespace mozilla {
/* static */
nscoord ColumnUtils::GetColumnGap(
const nsContainerFrame* aFrame,
nscoord aPercentageBasis) {
const auto& columnGap = aFrame->StylePosition()->mColumnGap;
if (columnGap.IsNormal()) {
return aFrame->StyleFont()->mFont.size.ToAppUnits();
}
return nsLayoutUtils::ResolveGapToLength(columnGap, aPercentageBasis);
}
/* static */
nscoord ColumnUtils::ClampUsedColumnWidth(
const Length& aColumnWidth) {
// Per spec, used values will be clamped to a minimum of 1px.
return std::max(CSSPixel::ToAppUnits(1), aColumnWidth.ToAppUnits());
}
/* static */
nscoord ColumnUtils::IntrinsicISize(uint32_t aColCount, nscoord aColGap,
nscoord aColISize) {
MOZ_ASSERT(aColCount > 0,
"Cannot compute with zero columns!");
// Column box's inline-size times number of columns (n), plus n-1 column gaps.
nscoord iSize = aColISize * aColCount + aColGap * (aColCount - 1);
// The multiplication above can make 'iSize' negative (integer overflow),
// so use std::max to protect against that.
return std::max(iSize, aColISize);
}
}
// namespace mozilla
