diff options
Diffstat (limited to 'library/main/src/com/android')
-rw-r--r-- | library/main/src/com/android/setupwizardlib/view/FillContentLayout.java | 125 | ||||
-rw-r--r-- | library/main/src/com/android/setupwizardlib/view/IntrinsicSizeFrameLayout.java | 6 |
2 files changed, 128 insertions, 3 deletions
diff --git a/library/main/src/com/android/setupwizardlib/view/FillContentLayout.java b/library/main/src/com/android/setupwizardlib/view/FillContentLayout.java new file mode 100644 index 0000000..2c28090 --- /dev/null +++ b/library/main/src/com/android/setupwizardlib/view/FillContentLayout.java @@ -0,0 +1,125 @@ +/* + * Copyright (C) 2017 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 com.android.setupwizardlib.view; + +import android.content.Context; +import android.content.res.TypedArray; +import android.util.AttributeSet; +import android.view.View; +import android.widget.FrameLayout; + +import com.android.setupwizardlib.R; + +/** + * A layout that will measure its children size based on the space it is given, by using its + * {@code android:minWidth}, {@code android:minHeight}, {@code android:maxWidth}, and + * {@code android:maxHeight} values. + * + * <p>Typically this is used to show an illustration image or video on the screen. For optimal UX, + * those assets typically want to occupy the remaining space available on screen within a certain + * range, and then stop scaling beyond the min/max size attributes. Therefore this view is typically + * used inside a ScrollView with {@code fillViewport} set to true, together with a linear layout + * weight or relative layout to fill the remaining space visible on screen. + * + * <p>When measuring, this view ignores its children and simply layout according to the minWidth / + * minHeight given. Therefore it is common for children of this layout to have width / height set to + * {@code match_parent}. The maxWidth / maxHeight values will then be applied to the children to + * make sure they are not too big. + */ +public class FillContentLayout extends FrameLayout { + + private int mMaxWidth; + private int mMaxHeight; + + public FillContentLayout(Context context) { + this(context, null); + } + + public FillContentLayout(Context context, AttributeSet attrs) { + this(context, attrs, R.attr.suwFillContentLayoutStyle); + } + + public FillContentLayout(Context context, AttributeSet attrs, int defStyleAttr) { + super(context, attrs, defStyleAttr); + init(context, attrs, defStyleAttr); + } + + private void init(Context context, AttributeSet attrs, int defStyleAttr) { + TypedArray a = context.obtainStyledAttributes( + attrs, + R.styleable.SuwFillContentLayout, + defStyleAttr, + 0); + + mMaxHeight = a.getDimensionPixelSize( + R.styleable.SuwFillContentLayout_android_maxHeight, -1); + mMaxWidth = a.getDimensionPixelSize(R.styleable.SuwFillContentLayout_android_maxWidth, -1); + + a.recycle(); + } + + @Override + protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { + // Measure this view with the minWidth and minHeight, without asking the children. + // (Children size is the drawable's intrinsic size, and we don't want that to influence + // the size of the illustration). + setMeasuredDimension( + getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec), + getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec)); + + int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + measureIllustrationChild(getChildAt(i), getMeasuredWidth(), getMeasuredHeight()); + } + } + + private void measureIllustrationChild(View child, int parentWidth, int parentHeight) { + // Modified from ViewGroup#measureChildWithMargins + final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams(); + + // Create measure specs that are no bigger than min(parentSize, maxSize) + + int childWidthMeasureSpec = getMaxSizeMeasureSpec( + Math.min(mMaxWidth, parentWidth), + getPaddingLeft() + getPaddingRight() + lp.leftMargin + lp.rightMargin, + lp.width); + int childHeightMeasureSpec = getMaxSizeMeasureSpec( + Math.min(mMaxHeight, parentHeight), + getPaddingTop() + getPaddingBottom() + lp.topMargin + lp.bottomMargin, + lp.height); + + child.measure(childWidthMeasureSpec, childHeightMeasureSpec); + } + + private static int getMaxSizeMeasureSpec(int maxSize, int padding, int childDimension) { + // Modified from ViewGroup#getChildMeasureSpec + int size = Math.max(0, maxSize - padding); + + if (childDimension >= 0) { + // Child wants a specific size... so be it + return MeasureSpec.makeMeasureSpec(childDimension, MeasureSpec.EXACTLY); + } else if (childDimension == LayoutParams.MATCH_PARENT) { + // Child wants to be our size. So be it. + return MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY); + } else if (childDimension == LayoutParams.WRAP_CONTENT) { + // Child wants to determine its own size. It can't be + // bigger than us. + return MeasureSpec.makeMeasureSpec(size, MeasureSpec.AT_MOST); + } + return 0; + } +} diff --git a/library/main/src/com/android/setupwizardlib/view/IntrinsicSizeFrameLayout.java b/library/main/src/com/android/setupwizardlib/view/IntrinsicSizeFrameLayout.java index e9ab1a7..02fdcc7 100644 --- a/library/main/src/com/android/setupwizardlib/view/IntrinsicSizeFrameLayout.java +++ b/library/main/src/com/android/setupwizardlib/view/IntrinsicSizeFrameLayout.java @@ -56,11 +56,11 @@ public class IntrinsicSizeFrameLayout extends FrameLayout { private void init(Context context, AttributeSet attrs, int defStyleAttr) { final TypedArray a = context.obtainStyledAttributes(attrs, - R.styleable.SuwMaxSizeFrameLayout, defStyleAttr, 0); + R.styleable.SuwIntrinsicSizeFrameLayout, defStyleAttr, 0); mIntrinsicHeight = - a.getDimensionPixelSize(R.styleable.SuwMaxSizeFrameLayout_android_height, 0); + a.getDimensionPixelSize(R.styleable.SuwIntrinsicSizeFrameLayout_android_height, 0); mIntrinsicWidth = - a.getDimensionPixelSize(R.styleable.SuwMaxSizeFrameLayout_android_width, 0); + a.getDimensionPixelSize(R.styleable.SuwIntrinsicSizeFrameLayout_android_width, 0); a.recycle(); } |