layout/base/nsAutoLayoutPhase.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef DEBUG
   7 static_assert(false, "This should not be compiled in !DEBUG");
   8 #endif // DEBUG
   9
  10 #include "nsAutoLayoutPhase.h"
  11 #include "nsPresContext.h"
  12 #include "nsContentUtils.h"
  13
  14 nsAutoLayoutPhase::nsAutoLayoutPhase(nsPresContext* aPresContext,
  15                                      nsLayoutPhase aPhase)
  16   : mPresContext(aPresContext)
  17   , mPhase(aPhase)
  18   , mCount(0)
  19 {
  20   Enter();
  21 }
  22
  23 nsAutoLayoutPhase::~nsAutoLayoutPhase()
  24 {
  25   Exit();
  26   MOZ_ASSERT(mCount == 0, "imbalanced");
  27 }
  28
  29 void
  30 nsAutoLayoutPhase::Enter()
  31 {
  32   switch (mPhase) {
  33     case eLayoutPhase_Paint:
  34       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Paint] == 0,
  35                  "recurring into paint");
  36       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Reflow] == 0,
  37                  "painting in the middle of reflow");
  38       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_FrameC] == 0,
  39                  "painting in the middle of frame construction");
  40       break;
  41     case eLayoutPhase_Reflow:
  42       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Paint] == 0,
  43                  "reflowing in the middle of a paint");
  44       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Reflow] == 0,
  45                  "recurring into reflow");
  46       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_FrameC] == 0,
  47                  "reflowing in the middle of frame construction");
  48       break;
  49     case eLayoutPhase_FrameC:
  50       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Paint] == 0,
  51                  "constructing frames in the middle of a paint");
  52       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_Reflow] == 0,
  53                  "constructing frames in the middle of reflow");
  54       MOZ_ASSERT(mPresContext->mLayoutPhaseCount[eLayoutPhase_FrameC] == 0,
  55                  "recurring into frame construction");
  56       MOZ_ASSERT(!nsContentUtils::IsSafeToRunScript(),
  57                  "constructing frames and scripts are not blocked");
  58       break;
  59     case eLayoutPhase_COUNT:
  60       break;
  61   }
  62
  63   ++(mPresContext->mLayoutPhaseCount[mPhase]);
  64   ++mCount;
  65 }
  66
  67 void
  68 nsAutoLayoutPhase::Exit()
  69 {
  70   MOZ_ASSERT(mCount > 0 && mPresContext->mLayoutPhaseCount[mPhase] > 0,
  71              "imbalanced");
  72   --(mPresContext->mLayoutPhaseCount[mPhase]);
  73   --mCount;
  74 }