Java tutorial
/* * Copyright 2012 Roman Nurik * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package id.co.datascrip.dtswarehousesystem.custom; import android.content.Context; import android.content.res.Resources; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.RectF; import android.support.v4.content.ContextCompat; import android.util.AttributeSet; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import id.co.datascrip.dtswarehousesystem.R; public class StepPagerStrip extends View { private static final int[] ATTRS = new int[] { android.R.attr.gravity }; private int mPageCount; private int mCurrentPage; private int mGravity = Gravity.START | Gravity.TOP; private float mTabWidth; private float mTabHeight; private float mTabSpacing; private Paint mPrevTabPaint; private Paint mSelectedTabPaint; private Paint mSelectedLastTabPaint; private Paint mNextTabPaint; private RectF mTempRectF = new RectF(); //private Scroller mScroller; private OnPageSelectedListener mOnPageSelectedListener; public StepPagerStrip(Context context) { this(context, null, 0); } public StepPagerStrip(Context context, AttributeSet attrs) { this(context, attrs, 0); } public StepPagerStrip(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); final TypedArray a = context.obtainStyledAttributes(attrs, ATTRS); mGravity = a.getInteger(0, mGravity); a.recycle(); final Resources res = getResources(); mTabWidth = res.getDimensionPixelSize(R.dimen.step_pager_tab_width); mTabHeight = res.getDimensionPixelSize(R.dimen.step_pager_tab_height); mTabSpacing = res.getDimensionPixelSize(R.dimen.step_pager_tab_spacing); mPrevTabPaint = new Paint(); mPrevTabPaint.setColor(ContextCompat.getColor(context, R.color.step_pager_previous_tab_color)); mSelectedTabPaint = new Paint(); mSelectedTabPaint.setColor(ContextCompat.getColor(context, R.color.step_pager_selected_tab_color)); mSelectedLastTabPaint = new Paint(); mSelectedLastTabPaint.setColor(ContextCompat.getColor(context, R.color.step_pager_selected_last_tab_color)); mNextTabPaint = new Paint(); mNextTabPaint.setColor(ContextCompat.getColor(context, R.color.step_pager_next_tab_color)); } public void setOnPageSelectedListener(OnPageSelectedListener onPageSelectedListener) { mOnPageSelectedListener = onPageSelectedListener; } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (mPageCount == 0) { return; } float totalWidth = mPageCount * (mTabWidth + mTabSpacing) - mTabSpacing; float totalLeft; boolean fillHorizontal = false; switch (mGravity & Gravity.HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: totalLeft = (getWidth() - totalWidth) / 2; break; case Gravity.END: totalLeft = getWidth() - getPaddingRight() - totalWidth; break; case Gravity.FILL_HORIZONTAL: totalLeft = getPaddingLeft(); fillHorizontal = true; break; default: totalLeft = getPaddingLeft(); } switch (mGravity & Gravity.VERTICAL_GRAVITY_MASK) { case Gravity.CENTER_VERTICAL: mTempRectF.top = (int) (getHeight() - mTabHeight) / 2; break; case Gravity.BOTTOM: mTempRectF.top = getHeight() - getPaddingBottom() - mTabHeight; break; default: mTempRectF.top = getPaddingTop(); } mTempRectF.bottom = mTempRectF.top + mTabHeight; float tabWidth = mTabWidth; if (fillHorizontal) { tabWidth = (getWidth() - getPaddingRight() - getPaddingLeft() - (mPageCount - 1) * mTabSpacing) / mPageCount; } for (int i = 0; i < mPageCount; i++) { mTempRectF.left = totalLeft + (i * (tabWidth + mTabSpacing)); mTempRectF.right = mTempRectF.left + tabWidth; canvas.drawRect(mTempRectF, i < mCurrentPage ? mPrevTabPaint : (i > mCurrentPage ? mNextTabPaint : (i == mPageCount - 1 ? mSelectedLastTabPaint : mSelectedTabPaint))); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension( View.resolveSize((int) (mPageCount * (mTabWidth + mTabSpacing) - mTabSpacing) + getPaddingLeft() + getPaddingRight(), widthMeasureSpec), View.resolveSize((int) mTabHeight + getPaddingTop() + getPaddingBottom(), heightMeasureSpec)); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { scrollCurrentPageIntoView(); super.onSizeChanged(w, h, oldw, oldh); } @Override public boolean onTouchEvent(MotionEvent event) { if (mOnPageSelectedListener != null) { switch (event.getActionMasked()) { case MotionEvent.ACTION_DOWN: case MotionEvent.ACTION_MOVE: int position = hitTest(event.getX()); if (position >= 0) { mOnPageSelectedListener.onPageStripSelected(position); } return true; } } return super.onTouchEvent(event); } private int hitTest(float x) { if (mPageCount == 0) { return -1; } float totalWidth = mPageCount * (mTabWidth + mTabSpacing) - mTabSpacing; float totalLeft; boolean fillHorizontal = false; switch (mGravity & Gravity.HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: totalLeft = (getWidth() - totalWidth) / 2; break; case Gravity.RIGHT: totalLeft = getWidth() - getPaddingRight() - totalWidth; break; case Gravity.FILL_HORIZONTAL: totalLeft = getPaddingLeft(); fillHorizontal = true; break; default: totalLeft = getPaddingLeft(); } float tabWidth = mTabWidth; if (fillHorizontal) { tabWidth = (getWidth() - getPaddingRight() - getPaddingLeft() - (mPageCount - 1) * mTabSpacing) / mPageCount; } float totalRight = totalLeft + (mPageCount * (tabWidth + mTabSpacing)); if (x >= totalLeft && x <= totalRight && totalRight > totalLeft) { return (int) (((x - totalLeft) / (totalRight - totalLeft)) * mPageCount); } else { return -1; } } public void setCurrentPage(int currentPage) { mCurrentPage = currentPage; invalidate(); scrollCurrentPageIntoView(); // TODO: Set content description appropriately } private void scrollCurrentPageIntoView() { // TODO: only works with left gravity for now // // float widthToActive = getPaddingLeft() + (mCurrentPage + 1) * (mTabWidth + mTabSpacing) // - mTabSpacing; // int viewWidth = getWidth(); // // int startScrollX = getScrollX(); // int destScrollX = (widthToActive > viewWidth) ? (int) (widthToActive - viewWidth) : 0; // // if (mScroller == null) { // mScroller = new Scroller(getContext()); // } // // mScroller.abortAnimation(); // mScroller.startScroll(startScrollX, 0, destScrollX - startScrollX, 0); // postInvalidate(); } public void setPageCount(int count) { mPageCount = count; invalidate(); // TODO: Set content description appropriately } public static interface OnPageSelectedListener { void onPageStripSelected(int position); } // // @Override // public void computeScroll() { // super.computeScroll(); // if (mScroller.computeScrollOffset()) { // setScrollX(mScroller.getCurrX()); // } // } }