1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/widget/xpwidgets/ContentHelper.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,108 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "ContentHelper.h"
1.10 +#include "nsQueryFrame.h"
1.11 +#include "nsIContent.h"
1.12 +#include "nsIScrollableFrame.h"
1.13 +#include "nsLayoutUtils.h"
1.14 +#include "nsStyleConsts.h"
1.15 +#include "nsView.h"
1.16 +
1.17 +namespace mozilla {
1.18 +namespace widget {
1.19 +
1.20 +uint32_t
1.21 +ContentHelper::GetTouchActionFromFrame(nsIFrame* aFrame)
1.22 +{
1.23 + if (!aFrame || !aFrame->GetContent() || !aFrame->GetContent()->GetPrimaryFrame()) {
1.24 + // If frame is invalid or null then return default value.
1.25 + return NS_STYLE_TOUCH_ACTION_AUTO;
1.26 + }
1.27 +
1.28 + if (!aFrame->IsFrameOfType(nsIFrame::eSVG) && !aFrame->IsFrameOfType(nsIFrame::eBlockFrame)) {
1.29 + // Since touch-action property can be applied to only svg and block-level
1.30 + // elements we ignore frames of other types.
1.31 + return NS_STYLE_TOUCH_ACTION_AUTO;
1.32 + }
1.33 +
1.34 + return (aFrame->GetContent()->GetPrimaryFrame()->StyleDisplay()->mTouchAction);
1.35 +}
1.36 +
1.37 +void
1.38 +ContentHelper::UpdateAllowedBehavior(uint32_t aTouchActionValue, bool aConsiderPanning, TouchBehaviorFlags& aOutBehavior)
1.39 +{
1.40 + if (aTouchActionValue != NS_STYLE_TOUCH_ACTION_AUTO) {
1.41 + // Double-tap-zooming need property value AUTO
1.42 + aOutBehavior &= ~AllowedTouchBehavior::DOUBLE_TAP_ZOOM;
1.43 + if (aTouchActionValue != NS_STYLE_TOUCH_ACTION_MANIPULATION) {
1.44 + // Pinch-zooming need value AUTO or MANIPULATION
1.45 + aOutBehavior &= ~AllowedTouchBehavior::PINCH_ZOOM;
1.46 + }
1.47 + }
1.48 +
1.49 + if (aConsiderPanning) {
1.50 + if (aTouchActionValue == NS_STYLE_TOUCH_ACTION_NONE) {
1.51 + aOutBehavior &= ~AllowedTouchBehavior::VERTICAL_PAN;
1.52 + aOutBehavior &= ~AllowedTouchBehavior::HORIZONTAL_PAN;
1.53 + }
1.54 +
1.55 + // Values pan-x and pan-y set at the same time to the same element do not affect panning constraints.
1.56 + // Therefore we need to check whether pan-x is set without pan-y and the same for pan-y.
1.57 + if ((aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_X) && !(aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_Y)) {
1.58 + aOutBehavior &= ~AllowedTouchBehavior::VERTICAL_PAN;
1.59 + } else if ((aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_Y) && !(aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_X)) {
1.60 + aOutBehavior &= ~AllowedTouchBehavior::HORIZONTAL_PAN;
1.61 + }
1.62 + }
1.63 +}
1.64 +
1.65 +ContentHelper::TouchBehaviorFlags
1.66 +ContentHelper::GetAllowedTouchBehavior(nsIWidget* aWidget, const nsIntPoint& aPoint)
1.67 +{
1.68 + nsView *view = nsView::GetViewFor(aWidget);
1.69 + nsIFrame *viewFrame = view->GetFrame();
1.70 +
1.71 + nsPoint relativePoint = nsLayoutUtils::GetEventCoordinatesRelativeTo(aWidget, aPoint, viewFrame);
1.72 +
1.73 + nsIFrame *target = nsLayoutUtils::GetFrameForPoint(viewFrame, relativePoint, nsLayoutUtils::IGNORE_ROOT_SCROLL_FRAME);
1.74 + nsIScrollableFrame *nearestScrollableParent = nsLayoutUtils::GetNearestScrollableFrame(target, 0);
1.75 + nsIFrame* nearestScrollableFrame = do_QueryFrame(nearestScrollableParent);
1.76 +
1.77 + // We're walking up the DOM tree until we meet the element with touch behavior and accumulating
1.78 + // touch-action restrictions of all elements in this chain.
1.79 + // The exact quote from the spec, that clarifies more:
1.80 + // To determine the effect of a touch, find the nearest ancestor (starting from the element itself)
1.81 + // that has a default touch behavior. Then examine the touch-action property of each element between
1.82 + // the hit tested element and the element with the default touch behavior (including both the hit
1.83 + // tested element and the element with the default touch behavior). If the touch-action property of
1.84 + // any of those elements disallows the default touch behavior, do nothing. Otherwise allow the element
1.85 + // to start considering the touch for the purposes of executing a default touch behavior.
1.86 +
1.87 + // Currently we support only two touch behaviors: panning and zooming.
1.88 + // For panning we walk up until we meet the first scrollable element (the element that supports panning)
1.89 + // or root element.
1.90 + // For zooming we walk up until the root element since Firefox currently supports only zooming of the
1.91 + // root frame but not the subframes.
1.92 +
1.93 + bool considerPanning = true;
1.94 + TouchBehaviorFlags behavior = AllowedTouchBehavior::VERTICAL_PAN | AllowedTouchBehavior::HORIZONTAL_PAN |
1.95 + AllowedTouchBehavior::PINCH_ZOOM | AllowedTouchBehavior::DOUBLE_TAP_ZOOM;
1.96 +
1.97 + for (nsIFrame *frame = target; frame && frame->GetContent() && behavior; frame = frame->GetParent()) {
1.98 + UpdateAllowedBehavior(GetTouchActionFromFrame(frame), considerPanning, behavior);
1.99 +
1.100 + if (frame == nearestScrollableFrame) {
1.101 + // We met the scrollable element, after it we shouldn't consider touch-action
1.102 + // values for the purpose of panning but only for zooming.
1.103 + considerPanning = false;
1.104 + }
1.105 + }
1.106 +
1.107 + return behavior;
1.108 +}
1.109 +
1.110 +}
1.111 +}
