Java 类android.support.v4.app.FragmentTransactionBugFixHack 实例源码

/**
 * 解决popTo多个fragment时动画引起的异常问题
 */
private void popToFix(String fragmentTag, int flag, final FragmentManager fragmentManager) {
    if (fragmentManager.getFragments() == null) return;

    mActivity.preparePopMultiple();
    fragmentManager.popBackStackImmediate(fragmentTag, flag);
    mActivity.popFinish();

    mHandler.post(new Runnable() {
        @Override
        public void run() {
            FragmentTransactionBugFixHack.reorderIndices(fragmentManager);
        }
    });
}

/**
 * 分发start事务
 *
 * @param from        当前Fragment
 * @param to          目标Fragment
 * @param requestCode requestCode
 * @param launchMode  启动模式
 * @param type        类型
 */
void dispatchStartTransaction(FragmentManager fragmentManager, SupportFragment from, SupportFragment to, int requestCode, int launchMode, int type) {
    fragmentManager = checkFragmentManager(fragmentManager, from);
    if (fragmentManager == null) return;

    if ((from != null && from.isRemoving())) {
        Log.e(TAG, from.getClass().getSimpleName() + " is poped, maybe you want to call startWithPop()!");
        return;
    }

    checkNotNull(to, "toFragment == null");

    if (from != null) {
        bindContainerId(from.getContainerId(), to);
    }

    // process SupportTransaction
    String toFragmentTag = to.getClass().getName();
    TransactionRecord transactionRecord = to.getTransactionRecord();
    if (transactionRecord != null) {
        if (transactionRecord.tag != null) {
            toFragmentTag = transactionRecord.tag;
        }

        if (transactionRecord.requestCode != null && transactionRecord.requestCode != 0) {
            requestCode = transactionRecord.requestCode;
            type = TYPE_ADD_RESULT;
        }

        if (transactionRecord.launchMode != null) {
            launchMode = transactionRecord.launchMode;
        }

        if (transactionRecord.withPop != null && transactionRecord.withPop) {
            type = TYPE_ADD_WITH_POP;
        }

        // 这里发现使用addSharedElement时,在被强杀重启时导致栈内顺序异常,这里进行一次hack顺序
        if (transactionRecord.sharedElementList != null) {
            FragmentTransactionBugFixHack.reorderIndices(fragmentManager);
        }
    }

    if (type == TYPE_ADD_RESULT) {
        saveRequestCode(to, requestCode);
    }

    if (handleLaunchMode(fragmentManager, to, toFragmentTag, launchMode)) return;

    switch (type) {
        case TYPE_ADD:
        case TYPE_ADD_RESULT:
            start(fragmentManager, from, to, toFragmentTag, transactionRecord == null ? null : transactionRecord.sharedElementList);
            break;
        case TYPE_ADD_WITH_POP:
            if (from != null) {
                startWithPop(fragmentManager, from, to, toFragmentTag);
            }
            break;
    }
}