page.dart 2.94 KB
/*
 * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'package:flutter/material.dart';

/// A class that holds rasterized pdf data
class PdfPreviewPageData {
  /// Default constructor
  const PdfPreviewPageData({
    required this.image,
    required this.width,
    required this.height,
  });

  /// rasterized pdf image provider
  final ImageProvider image;

  /// rasterized image width
  final int width;

  /// rasterized image height
  final int height;

  /// returns with to height aspect ratio
  double get aspectRatio {
    if (height != 0.0) {
      return width / height;
    }
    if (width > 0.0) {
      return double.infinity;
    }
    if (width < 0.0) {
      return double.negativeInfinity;
    }
    return 0.0;
  }

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is PdfPreviewPageData &&
          runtimeType == other.runtimeType &&
          image == other.image &&
          width == other.width &&
          height == other.height;

  @override
  int get hashCode => image.hashCode ^ width.hashCode ^ height.hashCode;
}

/// Represents one PDF page
class PdfPreviewPage extends StatelessWidget {
  /// Create a PDF page widget
  const PdfPreviewPage({
    super.key,
    required this.pageData,
    this.pdfPreviewPageDecoration,
    this.pageMargin,
  });

  /// Image representing the content of the page
  final PdfPreviewPageData pageData;

  /// Decoration around the page
  final Decoration? pdfPreviewPageDecoration;

  /// Margin
  final EdgeInsets? pageMargin;

  @override
  Widget build(BuildContext context) {
    final scrollbarTrack = Theme.of(context)
            .scrollbarTheme
            .thickness
            ?.resolve({WidgetState.hovered}) ??
        12;

    return Container(
      margin: pageMargin ??
          EdgeInsets.only(
            left: 8 + scrollbarTrack,
            top: 8,
            right: 8 + scrollbarTrack,
            bottom: 12,
          ),
      decoration: pdfPreviewPageDecoration ??
          const BoxDecoration(
            color: Colors.white,
            boxShadow: <BoxShadow>[
              BoxShadow(
                offset: Offset(0, 3),
                blurRadius: 5,
              ),
            ],
          ),
      child: AspectRatio(
        aspectRatio: pageData.aspectRatio,
        child: Image(
          image: pageData.image,
          fit: BoxFit.cover,
        ),
      ),
    );
  }
}