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Commit 7389eecb authored by Julian Mancini's avatar Julian Mancini
Browse files

Crop PDF Thumbnails before sending them from Provider 

Essentially, if you were to get a PDF Thumbnail for a landscape-oriented
ImageView (more horizontal than vertical), it would just squish the
whole PDF page down. This crops it so it looks nice in landscape and
portrait.

Bug: 63928143
Test: In place
Change-Id: Iaefabba1a96dcee5297bf6639aba8098c9137782
parent 6d423792

core/java/com/android/internal/content/PdfUtils.java

+70 −2
Original line number Diff line number Diff line
@@ -19,8 +19,8 @@ package com.android.internal.content; 
import android.annotation.Nullable;

import android.content.res.AssetFileDescriptor;

import android.graphics.Bitmap;

import android.graphics.Matrix;

import android.graphics.Point;

import android.graphics.Rect;

import android.graphics.pdf.PdfRenderer;

import android.os.AsyncTask;

import android.os.ParcelFileDescriptor;
@@ -56,10 +56,13 @@ public final class PdfUtils { 
                ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);

        PdfRenderer renderer = new PdfRenderer(pdfDescriptor);

        PdfRenderer.Page frontPage = renderer.openPage(0);

        Bitmap thumbnail = Bitmap.createBitmap(size.x, size.y,

        Bitmap thumbnail = Bitmap.createBitmap(frontPage.getWidth(), frontPage.getHeight(),

                Bitmap.Config.ARGB_8888);



        frontPage.render(thumbnail, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);



        thumbnail = crop(thumbnail, size.x, size.y, .5f, 0f);



        // Create an AssetFileDescriptor that contains the Bitmap's information

        final ByteArrayOutputStream out = new ByteArrayOutputStream();

        // Quality is an integer that determines how much compression is used.
@@ -93,4 +96,69 @@ public final class PdfUtils { 
        return new AssetFileDescriptor(fds[0], 0, AssetFileDescriptor.UNKNOWN_LENGTH);

    }



    /**

     * Returns a new Bitmap copy with a crop effect depending on the crop anchor given. 0.5f is like

     * {@link android.widget.ImageView.ScaleType#CENTER_CROP}. The crop anchor will be be nudged

     * so the entire cropped bitmap will fit inside the src. May return the input bitmap if no

     * scaling is necessary.

     *

     *

     * Example of changing verticalCenterPercent:

     *   _________            _________

     *  |         |          |         |

     *  |         |          |_________|

     *  |         |          |         |/___0.3f

     *  |---------|          |_________|\

     *  |         |<---0.5f  |         |

     *  |---------|          |         |

     *  |         |          |         |

     *  |         |          |         |

     *  |_________|          |_________|

     *

     * @param src original bitmap of any size

     * @param w desired width in px

     * @param h desired height in px

     * @param horizontalCenterPercent determines which part of the src to crop from. Range from 0

     *                                .0f to 1.0f. The value determines which part of the src

     *                                maps to the horizontal center of the resulting bitmap.

     * @param verticalCenterPercent determines which part of the src to crop from. Range from 0

     *                              .0f to 1.0f. The value determines which part of the src maps

     *                              to the vertical center of the resulting bitmap.

     * @return a copy of src conforming to the given width and height, or src itself if it already

     *         matches the given width and height

     *

     */

    private static Bitmap crop(final Bitmap src, final int w, final int h,

            final float horizontalCenterPercent, final float verticalCenterPercent) {

        if (horizontalCenterPercent < 0 || horizontalCenterPercent > 1 || verticalCenterPercent < 0

                || verticalCenterPercent > 1) {

            throw new IllegalArgumentException(

                    "horizontalCenterPercent and verticalCenterPercent must be between 0.0f and "

                            + "1.0f, inclusive.");

        }

        final int srcWidth = src.getWidth();

        final int srcHeight = src.getHeight();

        // exit early if no resize/crop needed

        if (w == srcWidth && h == srcHeight) {

            return src;

        }

        final Matrix m = new Matrix();

        final float scale = Math.max(

                (float) w / srcWidth,

                (float) h / srcHeight);

        m.setScale(scale, scale);

        final int srcCroppedW, srcCroppedH;

        int srcX, srcY;

        srcCroppedW = Math.round(w / scale);

        srcCroppedH = Math.round(h / scale);

        srcX = (int) (srcWidth * horizontalCenterPercent - srcCroppedW / 2);

        srcY = (int) (srcHeight * verticalCenterPercent - srcCroppedH / 2);

        // Nudge srcX and srcY to be within the bounds of src

        srcX = Math.max(Math.min(srcX, srcWidth - srcCroppedW), 0);

        srcY = Math.max(Math.min(srcY, srcHeight - srcCroppedH), 0);

        final Bitmap cropped = Bitmap.createBitmap(src, srcX, srcY,

                srcCroppedW, srcCroppedH, m, true);

        return cropped;

    }



}