问题
I am using MuPdf Android Library, I want vertical Scroll instead of horizontal page Scrolling, tried everything but failed, googled the problem and found an answer on Stackoverflow and someone answered his question which worked for the Questions Author but I am not getting this solution, putted these methods in ReaderView but by this way I found errors which were related to other activities, kindly help me to where put these methods etc. someone worked on mupdf vertical scrolling?
回答1:
As Arunjyothis said :
You can do by changing the horizontal values to vertical ( change all width related calculations to height )
Check the answer HERE.
回答2:
I created new binding library for Mupdf with method swipeHorizontal(boolean isHorizontal) so you can easy change between vertical and horizontal scroll
https://github.com/minaairsupport/MuPDF_Xamarin
Just download the library and reference it in your project
回答3:
You can do by changing the horizontal values to vertical ( change all width related calculations to height ). Change onLayout() & onFling() as below: (Reference)
@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// cv.getRight() may be out of date with the current scale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();
}
Also add the below lines:
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;
}
来源：https://stackoverflow.com/questions/33333069/mupdf-android-library-vertical-scroll