| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * 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 android.support.design.widget; |
| |
| import android.os.Build; |
| import android.support.v4.view.ViewCompat; |
| import android.view.View; |
| import android.view.ViewParent; |
| |
| /** |
| * Utility helper for moving a {@link android.view.View} around using |
| * {@link android.view.View#offsetLeftAndRight(int)} and |
| * {@link android.view.View#offsetTopAndBottom(int)}. |
| * <p> |
| * Also the setting of absolute offsets (similar to translationX/Y), rather than additive |
| * offsets. |
| */ |
| class ViewOffsetHelper { |
| |
| private final View mView; |
| |
| private int mLayoutTop; |
| private int mLayoutLeft; |
| private int mOffsetTop; |
| private int mOffsetLeft; |
| |
| public ViewOffsetHelper(View view) { |
| mView = view; |
| } |
| |
| public void onViewLayout() { |
| // Now grab the intended top |
| mLayoutTop = mView.getTop(); |
| mLayoutLeft = mView.getLeft(); |
| |
| // And offset it as needed |
| updateOffsets(); |
| } |
| |
| private void updateOffsets() { |
| ViewCompat.offsetTopAndBottom(mView, mOffsetTop - (mView.getTop() - mLayoutTop)); |
| ViewCompat.offsetLeftAndRight(mView, mOffsetLeft - (mView.getLeft() - mLayoutLeft)); |
| |
| // Manually invalidate the view and parent to make sure we get drawn pre-M |
| if (Build.VERSION.SDK_INT < 23) { |
| tickleInvalidationFlag(mView); |
| final ViewParent vp = mView.getParent(); |
| if (vp instanceof View) { |
| tickleInvalidationFlag((View) vp); |
| } |
| } |
| } |
| |
| private static void tickleInvalidationFlag(View view) { |
| final float x = ViewCompat.getTranslationX(view); |
| ViewCompat.setTranslationY(view, x + 1); |
| ViewCompat.setTranslationY(view, x); |
| } |
| |
| /** |
| * Set the top and bottom offset for this {@link ViewOffsetHelper}'s view. |
| * |
| * @param offset the offset in px. |
| * @return true if the offset has changed |
| */ |
| public boolean setTopAndBottomOffset(int offset) { |
| if (mOffsetTop != offset) { |
| mOffsetTop = offset; |
| updateOffsets(); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Set the left and right offset for this {@link ViewOffsetHelper}'s view. |
| * |
| * @param offset the offset in px. |
| * @return true if the offset has changed |
| */ |
| public boolean setLeftAndRightOffset(int offset) { |
| if (mOffsetLeft != offset) { |
| mOffsetLeft = offset; |
| updateOffsets(); |
| return true; |
| } |
| return false; |
| } |
| |
| public int getTopAndBottomOffset() { |
| return mOffsetTop; |
| } |
| |
| public int getLeftAndRightOffset() { |
| return mOffsetLeft; |
| } |
| } |