问题
I am developing app for android which has pdf to view. The PDF are in build into the app, so I have to just load pdf to view correctly.
There should be no option to share and all other stuff, but the user should be able to zoom the pdf.
I have used mupdf but the pdf scrolls horizontally (ie. the pages are side-by-side), I want the pdf to scroll vertically. I have tried everything but I am not getting result.
回答1:
You can do by changing the horizontal values to vertical ( change all width related calculations to height ). Change onLayout() & onFling() as below:
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
// "Edit mode" means when the View is being displayed in the Android GUI editor. (this class
// is instantiated in the IDE, so we need to be a bit careful what we do).
if (isInEditMode())
return;
View cv = mChildViews.get(mCurrent);
Point cvOffset;
if (!mResetLayout) {
// Move to next or previous if current is sufficiently off center
if (cv != null) {
cvOffset = subScreenSizeOffset(cv);
// cv.getRight() may be out of date with the current scale
// so add left to the measured width for the correct position
//if (cv.getLeft() + cv.getMeasuredWidth() + cvOffset.x + GAP/2 + mXScroll < getWidth()/2 && mCurrent + 1 < mAdapter.getCount()) {
if (cv.getTop() + cv.getMeasuredHeight() + cvOffset.y + GAP / 2 + mYScroll < getHeight() / 2 && mCurrent + 1 < mAdapter.getCount()) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
mStepper.prod();
onMoveOffChild(mCurrent);
mCurrent++;
onMoveToChild(mCurrent);
}
//if (cv.getLeft() - cvOffset.x - GAP/2 + mXScroll >= getWidth()/2 && mCurrent > 0) {
if (cv.getTop() - cvOffset.y - GAP / 2 + mYScroll >= getHeight() / 2 && mCurrent > 0) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
mStepper.prod();
onMoveOffChild(mCurrent);
mCurrent--;
onMoveToChild(mCurrent);
}
}
// Remove not needed children and hold them for reuse
int numChildren = mChildViews.size();
int childIndices[] = new int[numChildren];
for (int i = 0; i < numChildren; i++)
childIndices[i] = mChildViews.keyAt(i);
for (int i = 0; i < numChildren; i++) {
int ai = childIndices[i];
if (ai < mCurrent - 1 || ai > mCurrent + 1) {
View v = mChildViews.get(ai);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
mChildViews.remove(ai);
}
}
} else {
mResetLayout = false;
mXScroll = mYScroll = 0;
// Remove all children and hold them for reuse
int numChildren = mChildViews.size();
for (int i = 0; i < numChildren; i++) {
View v = mChildViews.valueAt(i);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
}
mChildViews.clear();
// Don't reuse cached views if the adapter has changed
if (mReflowChanged) {
mReflowChanged = false;
mViewCache.clear();
}
// post to ensure generation of hq area
mStepper.prod();
}
// Ensure current view is present
int cvLeft, cvRight, cvTop, cvBottom;
boolean notPresent = (mChildViews.get(mCurrent) == null);
cv = getOrCreateChild(mCurrent);
// When the view is sub-screen-size in either dimension we
// offset it to center within the screen area, and to keep
// the views spaced out
cvOffset = subScreenSizeOffset(cv);
if (notPresent) {
//Main item not already present. Just place it top left
cvLeft = cvOffset.x;
cvTop = cvOffset.y;
} else {
// Main item already present. Adjust by scroll offsets
cvLeft = cv.getLeft() + mXScroll;
cvTop = cv.getTop() + mYScroll;
}
// Scroll values have been accounted for
mXScroll = mYScroll = 0;
cvRight = cvLeft + cv.getMeasuredWidth();
cvBottom = cvTop + cv.getMeasuredHeight();
if (!mUserInteracting && mScroller.isFinished()) {
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvRight += corr.x;
cvLeft += corr.x;
cvTop += corr.y;
cvBottom += corr.y;
} else if (cv.getMeasuredWidth() <= getWidth()) {
// // When the current view is as small as the screen in height, clamp
// // it vertically
// Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
// cvTop += corr.y;
// cvBottom += corr.y;
// When the current view is as small as the screen in width, clamp
// it horizontally
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvRight += corr.x;
cvLeft += corr.x;
}
cv.layout(cvLeft, cvTop, cvRight, cvBottom);
if (mCurrent > 0) {
View lv = getOrCreateChild(mCurrent - 1);
Point leftOffset = subScreenSizeOffset(lv);
/*int gap = leftOffset.x + GAP + cvOffset.x;
lv.layout(cvLeft - lv.getMeasuredWidth() - gap,
(cvBottom + cvTop - lv.getMeasuredHeight())/2,
cvLeft - gap,
(cvBottom + cvTop + lv.getMeasuredHeight())/2);*/
int gap = leftOffset.y + GAP + cvOffset.y;
lv.layout((cvRight + cvLeft - lv.getMeasuredWidth())/2,
cvTop - lv.getMeasuredHeight() - gap,
(cvRight + cvLeft + lv.getMeasuredWidth())/2,
cvTop - gap);
}
if (mCurrent + 1 < mAdapter.getCount()) {
View rv = getOrCreateChild(mCurrent + 1);
Point rightOffset = subScreenSizeOffset(rv);
/*int gap = cvOffset.x + GAP + rightOffset.x;
rv.layout(cvRight + gap,
(cvBottom + cvTop - rv.getMeasuredHeight())/2,
cvRight + rv.getMeasuredWidth() + gap,
(cvBottom + cvTop + rv.getMeasuredHeight())/2);*/
int gap = cvOffset.y + GAP + rightOffset.y;
rv.layout((cvRight + cvLeft - rv.getMeasuredWidth())/2,
cvBottom + gap,
(cvRight + cvLeft + rv.getMeasuredWidth())/2,
cvBottom + rv.getMeasuredHeight() + gap);
}
invalidate();
}
And,
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (mScaling)
return true;
View v = mChildViews.get(mCurrent);
if (v != null) {
Rect bounds = getScrollBounds(v);
switch (directionOfTravel(velocityX, velocityY)) {
case MOVING_UP:
if (bounds.top >= 0) {
// Fling off to the left bring next view onto screen
View vl = mChildViews.get(mCurrent + 1);
if (vl != null) {
slideViewOntoScreen(vl);
return true;
}
}
break;
case MOVING_DOWN:
if (bounds.bottom <= 0) {
// Fling off to the right bring previous view onto screen
View vr = mChildViews.get(mCurrent - 1);
if (vr != null) {
slideViewOntoScreen(vr);
return true;
}
}
break;
}
mScrollerLastX = mScrollerLastY = 0;
// If the page has been dragged out of bounds then we want to spring back
// nicely. fling jumps back into bounds instantly, so we don't want to use
// fling in that case. On the other hand, we don't want to forgo a fling
// just because of a slightly off-angle drag taking us out of bounds other
// than in the direction of the drag, so we test for out of bounds only
// in the direction of travel.
//
// Also don't fling if out of bounds in any direction by more than fling
// margin
Rect expandedBounds = new Rect(bounds);
expandedBounds.inset(-FLING_MARGIN, -FLING_MARGIN);
if (withinBoundsInDirectionOfTravel(bounds, velocityX, velocityY)
&& expandedBounds.contains(0, 0)) {
mScroller.fling(0, 0, (int) velocityX, (int) velocityY, bounds.left, bounds.right, bounds.top, bounds.bottom);
mStepper.prod();
}
}
return true;
}
回答2:
The solution to this for MuPDF 1.9a is simply changing the following variable in the file ReaderView.java;
private static final boolean HORIZONTAL_SCROLLING = true;
to
private static final boolean HORIZONTAL_SCROLLING = false;
回答3:
Thx for answer posted by @Arunjyothis but i have provided below class where variable reference are present :
ReaderView.java
public class ReaderView extends AdapterView<Adapter>
implements GestureDetector.OnGestureListener, ScaleGestureDetector.OnScaleGestureListener, Runnable {
...
private Stepper mStepper;
public ReaderView(Context context) {
super(context);
mGestureDetector = new GestureDetector(this);
mScaleGestureDetector = new ScaleGestureDetector(context, this);
mScroller = new Scroller(context);
mStepper = new Stepper(this, this);
}
boolean mReflowChanged;
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
// "Edit mode" means when the View is being displayed in the Android GUI editor. (this class
// is instantiated in the IDE, so we need to be a bit careful what we do).
if (isInEditMode())
return;
View cv = mChildViews.get(mCurrent);
Point cvOffset;
if (!mResetLayout) {
// Move to next or previous if current is sufficiently off center
if (cv != null) {
cvOffset = subScreenSizeOffset(cv);
// cv.getRight() may be out of date with the current scale
// so add left to the measured width for the correct position
//if (cv.getLeft() + cv.getMeasuredWidth() + cvOffset.x + GAP/2 + mXScroll < getWidth()/2 && mCurrent + 1 < mAdapter.getCount()) {
if (cv.getTop() + cv.getMeasuredHeight() + cvOffset.y + GAP / 2 + mYScroll < getHeight() / 2 && mCurrent + 1 < mAdapter.getCount()) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
mStepper.prod();
onMoveOffChild(mCurrent);
mCurrent++;
onMoveToChild(mCurrent);
}
//if (cv.getLeft() - cvOffset.x - GAP/2 + mXScroll >= getWidth()/2 && mCurrent > 0) {
if (cv.getTop() - cvOffset.y - GAP / 2 + mYScroll >= getHeight() / 2 && mCurrent > 0) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
mStepper.prod();
onMoveOffChild(mCurrent);
mCurrent--;
onMoveToChild(mCurrent);
}
}
// Remove not needed children and hold them for reuse
int numChildren = mChildViews.size();
int childIndices[] = new int[numChildren];
for (int i = 0; i < numChildren; i++)
childIndices[i] = mChildViews.keyAt(i);
for (int i = 0; i < numChildren; i++) {
int ai = childIndices[i];
if (ai < mCurrent - 1 || ai > mCurrent + 1) {
View v = mChildViews.get(ai);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
mChildViews.remove(ai);
}
}
} else {
mResetLayout = false;
mXScroll = mYScroll = 0;
// Remove all children and hold them for reuse
int numChildren = mChildViews.size();
for (int i = 0; i < numChildren; i++) {
View v = mChildViews.valueAt(i);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
}
mChildViews.clear();
// Don't reuse cached views if the adapter has changed
if (mReflowChanged) {
mReflowChanged = false;
mViewCache.clear();
}
// post to ensure generation of hq area
mStepper.prod();
}
// Ensure current view is present
int cvLeft, cvRight, cvTop, cvBottom;
boolean notPresent = (mChildViews.get(mCurrent) == null);
cv = getOrCreateChild(mCurrent);
// When the view is sub-screen-size in either dimension we
// offset it to center within the screen area, and to keep
// the views spaced out
cvOffset = subScreenSizeOffset(cv);
if (notPresent) {
//Main item not already present. Just place it top left
cvLeft = cvOffset.x;
cvTop = cvOffset.y;
} else {
// Main item already present. Adjust by scroll offsets
cvLeft = cv.getLeft() + mXScroll;
cvTop = cv.getTop() + mYScroll;
}
// Scroll values have been accounted for
mXScroll = mYScroll = 0;
cvRight = cvLeft + cv.getMeasuredWidth();
cvBottom = cvTop + cv.getMeasuredHeight();
if (!mUserInteracting && mScroller.isFinished()) {
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvRight += corr.x;
cvLeft += corr.x;
cvTop += corr.y;
cvBottom += corr.y;
} else if (cv.getMeasuredWidth() <= getWidth()) {
// // When the current view is as small as the screen in height, clamp
// // it vertically
// Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
// cvTop += corr.y;
// cvBottom += corr.y;
// When the current view is as small as the screen in width, clamp
// it horizontally
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvRight += corr.x;
cvLeft += corr.x;
}
cv.layout(cvLeft, cvTop, cvRight, cvBottom);
if (mCurrent > 0) {
View lv = getOrCreateChild(mCurrent - 1);
Point leftOffset = subScreenSizeOffset(lv);
/*int gap = leftOffset.x + GAP + cvOffset.x;
lv.layout(cvLeft - lv.getMeasuredWidth() - gap,
(cvBottom + cvTop - lv.getMeasuredHeight())/2,
cvLeft - gap,
(cvBottom + cvTop + lv.getMeasuredHeight())/2);*/
int gap = leftOffset.y + GAP + cvOffset.y;
lv.layout((cvRight + cvLeft - lv.getMeasuredWidth()) / 2,
cvTop - lv.getMeasuredHeight() - gap,
(cvRight + cvLeft + lv.getMeasuredWidth()) / 2,
cvTop - gap);
}
if (mCurrent + 1 < mAdapter.getCount()) {
View rv = getOrCreateChild(mCurrent + 1);
Point rightOffset = subScreenSizeOffset(rv);
/*int gap = cvOffset.x + GAP + rightOffset.x;
rv.layout(cvRight + gap,
(cvBottom + cvTop - rv.getMeasuredHeight())/2,
cvRight + rv.getMeasuredWidth() + gap,
(cvBottom + cvTop + rv.getMeasuredHeight())/2);*/
int gap = cvOffset.y + GAP + rightOffset.y;
rv.layout((cvRight + cvLeft - rv.getMeasuredWidth()) / 2,
cvBottom + gap,
(cvRight + cvLeft + rv.getMeasuredWidth()) / 2,
cvBottom + rv.getMeasuredHeight() + gap);
}
invalidate();
}
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (mScaling)
return true;
View v = mChildViews.get(mCurrent);
if (v != null) {
Rect bounds = getScrollBounds(v);
switch (directionOfTravel(velocityX, velocityY)) {
case MOVING_UP:
if (bounds.top >= 0) {
// Fling off to the left bring next view onto screen
View vl = mChildViews.get(mCurrent + 1);
if (vl != null) {
slideViewOntoScreen(vl);
return true;
}
}
break;
case MOVING_DOWN:
if (bounds.bottom <= 0) {
// Fling off to the right bring previous view onto screen
View vr = mChildViews.get(mCurrent - 1);
if (vr != null) {
slideViewOntoScreen(vr);
return true;
}
}
break;
}
mScrollerLastX = mScrollerLastY = 0;
// If the page has been dragged out of bounds then we want to spring back
// nicely. fling jumps back into bounds instantly, so we don't want to use
// fling in that case. On the other hand, we don't want to forgo a fling
// just because of a slightly off-angle drag taking us out of bounds other
// than in the direction of the drag, so we test for out of bounds only
// in the direction of travel.
//
// Also don't fling if out of bounds in any direction by more than fling
// margin
Rect expandedBounds = new Rect(bounds);
expandedBounds.inset(-FLING_MARGIN, -FLING_MARGIN);
if (withinBoundsInDirectionOfTravel(bounds, velocityX, velocityY)
&& expandedBounds.contains(0, 0)) {
mScroller.fling(0, 0, (int) velocityX, (int) velocityY, bounds.left, bounds.right, bounds.top, bounds.bottom);
mStepper.prod();
}
}
return true;
}
...
}
Stepper.java
public class Stepper {
protected final View mPoster;
protected final Runnable mTask;
protected boolean mPending;
public Stepper(View v, Runnable r) {
mPoster = v;
mTask = r;
mPending = false;
}
@SuppressLint("NewApi")
public void prod() {
if (!mPending) {
mPending = true;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mPoster.postOnAnimation(new Runnable() {
@Override
public void run() {
mPending = false;
mTask.run();
}
});
} else {
mPoster.post(new Runnable() {
@Override
public void run() {
mPending = false;
mTask.run();
}
});
}
}
}
}
来源：https://stackoverflow.com/questions/25073116/android-pdf-viewer-with-vertical-paging