michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "ContentHelper.h"
michael@0: #include "nsQueryFrame.h"
michael@0: #include "nsIContent.h"
michael@0: #include "nsIScrollableFrame.h"
michael@0: #include "nsLayoutUtils.h"
michael@0: #include "nsStyleConsts.h"
michael@0: #include "nsView.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace widget {
michael@0: 
michael@0: uint32_t
michael@0: ContentHelper::GetTouchActionFromFrame(nsIFrame* aFrame)
michael@0: {
michael@0:   if (!aFrame || !aFrame->GetContent() || !aFrame->GetContent()->GetPrimaryFrame()) {
michael@0:     // If frame is invalid or null then return default value.
michael@0:     return NS_STYLE_TOUCH_ACTION_AUTO;
michael@0:   }
michael@0: 
michael@0:   if (!aFrame->IsFrameOfType(nsIFrame::eSVG) && !aFrame->IsFrameOfType(nsIFrame::eBlockFrame)) {
michael@0:     // Since touch-action property can be applied to only svg and block-level
michael@0:     // elements we ignore frames of other types.
michael@0:     return NS_STYLE_TOUCH_ACTION_AUTO;
michael@0:   }
michael@0: 
michael@0:   return (aFrame->GetContent()->GetPrimaryFrame()->StyleDisplay()->mTouchAction);
michael@0: }
michael@0: 
michael@0: void
michael@0: ContentHelper::UpdateAllowedBehavior(uint32_t aTouchActionValue, bool aConsiderPanning, TouchBehaviorFlags& aOutBehavior)
michael@0: {
michael@0:   if (aTouchActionValue != NS_STYLE_TOUCH_ACTION_AUTO) {
michael@0:     // Double-tap-zooming need property value AUTO
michael@0:     aOutBehavior &= ~AllowedTouchBehavior::DOUBLE_TAP_ZOOM;
michael@0:     if (aTouchActionValue != NS_STYLE_TOUCH_ACTION_MANIPULATION) {
michael@0:       // Pinch-zooming need value AUTO or MANIPULATION
michael@0:       aOutBehavior &= ~AllowedTouchBehavior::PINCH_ZOOM;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (aConsiderPanning) {
michael@0:     if (aTouchActionValue == NS_STYLE_TOUCH_ACTION_NONE) {
michael@0:       aOutBehavior &= ~AllowedTouchBehavior::VERTICAL_PAN;
michael@0:       aOutBehavior &= ~AllowedTouchBehavior::HORIZONTAL_PAN;
michael@0:     }
michael@0: 
michael@0:     // Values pan-x and pan-y set at the same time to the same element do not affect panning constraints.
michael@0:     // Therefore we need to check whether pan-x is set without pan-y and the same for pan-y.
michael@0:     if ((aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_X) && !(aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_Y)) {
michael@0:       aOutBehavior &= ~AllowedTouchBehavior::VERTICAL_PAN;
michael@0:     } else if ((aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_Y) && !(aTouchActionValue & NS_STYLE_TOUCH_ACTION_PAN_X)) {
michael@0:       aOutBehavior &= ~AllowedTouchBehavior::HORIZONTAL_PAN;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: ContentHelper::TouchBehaviorFlags
michael@0: ContentHelper::GetAllowedTouchBehavior(nsIWidget* aWidget, const nsIntPoint& aPoint)
michael@0: {
michael@0:   nsView *view = nsView::GetViewFor(aWidget);
michael@0:   nsIFrame *viewFrame = view->GetFrame();
michael@0: 
michael@0:   nsPoint relativePoint = nsLayoutUtils::GetEventCoordinatesRelativeTo(aWidget, aPoint, viewFrame);
michael@0: 
michael@0:   nsIFrame *target = nsLayoutUtils::GetFrameForPoint(viewFrame, relativePoint, nsLayoutUtils::IGNORE_ROOT_SCROLL_FRAME);
michael@0:   nsIScrollableFrame *nearestScrollableParent = nsLayoutUtils::GetNearestScrollableFrame(target, 0);
michael@0:   nsIFrame* nearestScrollableFrame = do_QueryFrame(nearestScrollableParent);
michael@0: 
michael@0:   // We're walking up the DOM tree until we meet the element with touch behavior and accumulating
michael@0:   // touch-action restrictions of all elements in this chain.
michael@0:   // The exact quote from the spec, that clarifies more:
michael@0:   // To determine the effect of a touch, find the nearest ancestor (starting from the element itself)
michael@0:   // that has a default touch behavior. Then examine the touch-action property of each element between
michael@0:   // the hit tested element and the element with the default touch behavior (including both the hit
michael@0:   // tested element and the element with the default touch behavior). If the touch-action property of
michael@0:   // any of those elements disallows the default touch behavior, do nothing. Otherwise allow the element
michael@0:   // to start considering the touch for the purposes of executing a default touch behavior.
michael@0: 
michael@0:   // Currently we support only two touch behaviors: panning and zooming.
michael@0:   // For panning we walk up until we meet the first scrollable element (the element that supports panning)
michael@0:   // or root element.
michael@0:   // For zooming we walk up until the root element since Firefox currently supports only zooming of the
michael@0:   // root frame but not the subframes.
michael@0: 
michael@0:   bool considerPanning = true;
michael@0:   TouchBehaviorFlags behavior = AllowedTouchBehavior::VERTICAL_PAN | AllowedTouchBehavior::HORIZONTAL_PAN |
michael@0:                                 AllowedTouchBehavior::PINCH_ZOOM | AllowedTouchBehavior::DOUBLE_TAP_ZOOM;
michael@0: 
michael@0:   for (nsIFrame *frame = target; frame && frame->GetContent() && behavior; frame = frame->GetParent()) {
michael@0:     UpdateAllowedBehavior(GetTouchActionFromFrame(frame), considerPanning, behavior);
michael@0: 
michael@0:     if (frame == nearestScrollableFrame) {
michael@0:       // We met the scrollable element, after it we shouldn't consider touch-action
michael@0:       // values for the purpose of panning but only for zooming.
michael@0:       considerPanning = false;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return behavior;
michael@0: }
michael@0: 
michael@0: }
michael@0: }