github.com/pdfcpu/pdfcpu@v0.11.1/pkg/api/rotate.go (about)

     1  /*
     2  	Copyright 2020 The pdfcpu Authors.
     3  
     4  	Licensed under the Apache License, Version 2.0 (the "License");
     5  	you may not use this file except in compliance with the License.
     6  	You may obtain a copy of the License at
     7  
     8  		http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  	Unless required by applicable law or agreed to in writing, software
    11  	distributed under the License is distributed on an "AS IS" BASIS,
    12  	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  	See the License for the specific language governing permissions and
    14  	limitations under the License.
    15  */
    16  
    17  package api
    18  
    19  import (
    20  	"io"
    21  	"os"
    22  
    23  	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu"
    24  	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu/model"
    25  	"github.com/pkg/errors"
    26  )
    27  
    28  // Rotate rotates selected pages of rs clockwise by rotation degrees and writes the result to w.
    29  func Rotate(rs io.ReadSeeker, w io.Writer, rotation int, selectedPages []string, conf *model.Configuration) error {
    30  	if rs == nil {
    31  		return errors.New("pdfcpu: Rotate: missing rs")
    32  	}
    33  
    34  	if conf == nil {
    35  		conf = model.NewDefaultConfiguration()
    36  	}
    37  	conf.Cmd = model.ROTATE
    38  
    39  	ctx, err := ReadValidateAndOptimize(rs, conf)
    40  	if err != nil {
    41  		return err
    42  	}
    43  
    44  	pages, err := PagesForPageSelection(ctx.PageCount, selectedPages, true, true)
    45  	if err != nil {
    46  		return err
    47  	}
    48  
    49  	if err = pdfcpu.RotatePages(ctx, pages, rotation); err != nil {
    50  		return err
    51  	}
    52  
    53  	return Write(ctx, w, conf)
    54  }
    55  
    56  // RotateFile rotates selected pages of inFile clockwise by rotation degrees and writes the result to outFile.
    57  func RotateFile(inFile, outFile string, rotation int, selectedPages []string, conf *model.Configuration) (err error) {
    58  	var f1, f2 *os.File
    59  
    60  	if f1, err = os.Open(inFile); err != nil {
    61  		return err
    62  	}
    63  
    64  	tmpFile := inFile + ".tmp"
    65  	if outFile != "" && inFile != outFile {
    66  		tmpFile = outFile
    67  		logWritingTo(outFile)
    68  	} else {
    69  		logWritingTo(inFile)
    70  	}
    71  	if f2, err = os.Create(tmpFile); err != nil {
    72  		f1.Close()
    73  		return err
    74  	}
    75  
    76  	defer func() {
    77  		if err != nil {
    78  			f2.Close()
    79  			f1.Close()
    80  			os.Remove(tmpFile)
    81  			return
    82  		}
    83  		if err = f2.Close(); err != nil {
    84  			return
    85  		}
    86  		if err = f1.Close(); err != nil {
    87  			return
    88  		}
    89  		if outFile == "" || inFile == outFile {
    90  			err = os.Rename(tmpFile, inFile)
    91  		}
    92  	}()
    93  
    94  	return Rotate(f1, f2, rotation, selectedPages, conf)
    95  }