Android的PDF阅读器垂直分页 [英] android pdf viewer with vertical paging
本文介绍了Android的PDF阅读器垂直分页的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我开发的应用程序为Android具有PDF查看。该PDF是构建成应用程序，所以我必须只加载PDF格式正确看待。
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.
不应该有选择共享和所有其他的东西，但用户应该能够放大的PDF。
There should be no option to share and all other stuff, but the user should be able to zoom the pdf.
我已经使用mupdf但PDF水平滚动（即页面是并排侧），我想要的PDF垂直滚动。我曾尝试一切，但我没有得到结果。
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.
推荐答案
您可以通过更改水平值，垂直（更改所有宽度相关的计算，以高度）做的。改变onLayout（）及onFling（）如下：
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// cv.getRight() may be out of date with the current scale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();
}
和
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;
}
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