com.backendless.persistence.PagedQueryBuilder Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of backendless Show documentation

Android SDK used by developers to provide Backendless API in apps.

There is a newer version: 7.0-alpha

package com.backendless.persistence;

import com.backendless.exceptions.ExceptionMessage;

class PagedQueryBuilder
{
  private int pageSize;
  private int offset;

  private Builder builder;

  PagedQueryBuilder( Builder builder )
  {
    pageSize = BackendlessDataQuery.DEFAULT_PAGE_SIZE;
    offset = BackendlessDataQuery.DEFAULT_OFFSET;
    this.builder = builder;
  }

  Builder setPageSize( int pageSize )
  {
    validatePageSize( pageSize );
    this.pageSize = pageSize;
    return builder;
  }

  Builder setOffset( int offset )
  {
    validateOffset( offset );
    this.offset = offset;
    return builder;
  }

  /**
   * Updates offset to point at next data page by adding pageSize.
   */
  Builder prepareNextPage()
  {
    int offset = this.offset + pageSize;
    validateOffset( offset );
    this.offset = offset;

    return builder;
  }

  /**
   * Updates offset to point at previous data page by subtracting pageSize.
   */
  Builder preparePreviousPage()
  {
    int offset = this.offset - pageSize;
    validateOffset( offset );
    this.offset = offset;

    return builder;
  }

  BackendlessDataQuery build()
  {
    validateOffset( offset );
    validatePageSize( pageSize );

    BackendlessDataQuery dataQuery = new BackendlessDataQuery();
    dataQuery.setPageSize( pageSize );
    dataQuery.setOffset( offset );

    return dataQuery;
  }


  private void validateOffset( int offset )
  {
    if( offset < 0 )
      throw new IllegalArgumentException( ExceptionMessage.WRONG_OFFSET );
  }

  private void validatePageSize( int pageSize )
  {
    if( pageSize <= 0 )
      throw new IllegalArgumentException( ExceptionMessage.WRONG_PAGE_SIZE );
  }

}