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-rw-r--r--res/layout/display.xml2
-rw-r--r--src/com/android/calculator2/Calculator.java42
-rw-r--r--src/com/android/calculator2/CalculatorResult.java89
-rw-r--r--src/com/android/calculator2/Evaluator.java9
4 files changed, 90 insertions, 52 deletions
diff --git a/res/layout/display.xml b/res/layout/display.xml
index 1fe2cf7..d50d09f 100644
--- a/res/layout/display.xml
+++ b/res/layout/display.xml
@@ -53,7 +53,7 @@
<!--
We lay the result out to full width, but are careful to use only
- 2/3 of the space, so that we have room when we expand.
+ 4/5 of the space, so that we have room when we expand.
-->
<com.android.calculator2.CalculatorResult
android:id="@+id/result"
diff --git a/src/com/android/calculator2/Calculator.java b/src/com/android/calculator2/Calculator.java
index d5242fa..e2c006c 100644
--- a/src/com/android/calculator2/Calculator.java
+++ b/src/com/android/calculator2/Calculator.java
@@ -19,11 +19,7 @@
// Other menus are not handled brilliantly either.
// TODO: Revisit handling of "Help" menu, so that it's more consistent
// with our conventions.
-// TODO: See if we can make scrolling look better, especially on small
-// displays. Fix evaluation interface so the evaluator returns entire
-// result, and formatting of exponent etc. is done separately.
// TODO: Better indication of when the result is known to be exact.
-// TODO: Fix placement of inverse trig buttons.
// TODO: Check and possibly fix accessability issues.
// TODO: Copy & more general paste in formula? Note that this requires
// great care: Currently the text version of a displayed formula
@@ -466,15 +462,12 @@ public class Calculator extends Activity
}
// Initial evaluation completed successfully. Initiate display.
- public void onEvaluate(int initDisplayPrec, String truncatedWholeNumber) {
+ public void onEvaluate(int initDisplayPrec, int leastDigPos, String truncatedWholeNumber) {
// Invalidate any options that may depend on the current result.
invalidateOptionsMenu();
- if (mCurrentState == CalculatorState.INPUT) {
- // Just update small result display.
- mResult.displayResult(initDisplayPrec, truncatedWholeNumber);
- } else { // in EVALUATE or INIT state
- mResult.displayResult(initDisplayPrec, truncatedWholeNumber);
+ mResult.displayResult(initDisplayPrec, leastDigPos, truncatedWholeNumber);
+ if (mCurrentState != CalculatorState.INPUT) { // in EVALUATE or INIT state
onResult(mCurrentState != CalculatorState.INIT);
}
}
@@ -646,20 +639,19 @@ public class Calculator extends Activity
// We assume the result already contains the text to be expanded.
private void onResult(boolean animate) {
// Calculate the values needed to perform the scale and translation animations.
- // We now fix the character size in the display to avoid weird effects
- // when we scroll.
- // Display.xml is designed to ensure exactly a 3/2 ratio between the formula
- // slot and small result slot.
- final float resultScale = 1.5f;
- final float resultTranslationX = -mResult.getWidth() * (resultScale - 1)/2;
- // mFormulaText is aligned with mResult on the right.
- // When we enlarge it around its center, the right side
- // moves to the right. This compensates.
- float resultTranslationY = -mResult.getHeight();
- // This is how much we want to move the bottom.
- // Now compensate for the fact that we're
- // simultaenously expanding it around its center by half its height
- resultTranslationY += mResult.getHeight() * (resultScale - 1)/2;
+ // The nominal font size in the result display is fixed. But the magnification we
+ // use when the user hits "=" is variable, with a scrollable result always getting
+ // minimum magnification.
+ // Display.xml is designed to ensure that a 5/4 increase is always possible.
+ // More is possible if the display is not fully occupied.
+ // Pivot the result around the bottom of the text.
+ final float resultScale = (float)Math.min(1.25f / mResult.getOccupancy(), 2.0);
+ // Keep the right end of text fixed as we scale.
+ mResult.setPivotX(mResult.getWidth() - mResult.getPaddingRight());
+ // Move result up to take place of formula. Scale around top of formula.
+ mResult.setPivotY(mResult.getPaddingTop());
+ float resultTranslationY = -mFormulaText.getHeight();
+ // Move formula off screen.
final float formulaTranslationY = -mFormulaText.getBottom();
// TODO: Reintroduce textColorAnimator?
@@ -672,7 +664,6 @@ public class Calculator extends Activity
animatorSet.playTogether(
ObjectAnimator.ofFloat(mResult, View.SCALE_X, resultScale),
ObjectAnimator.ofFloat(mResult, View.SCALE_Y, resultScale),
- ObjectAnimator.ofFloat(mResult, View.TRANSLATION_X, resultTranslationX),
ObjectAnimator.ofFloat(mResult, View.TRANSLATION_Y, resultTranslationY),
ObjectAnimator.ofFloat(mFormulaText, View.TRANSLATION_Y,
formulaTranslationY));
@@ -697,7 +688,6 @@ public class Calculator extends Activity
} else /* No animation desired; get there fast, e.g. when restarting */ {
mResult.setScaleX(resultScale);
mResult.setScaleY(resultScale);
- mResult.setTranslationX(resultTranslationX);
mResult.setTranslationY(resultTranslationY);
mFormulaText.setTranslationY(formulaTranslationY);
setState(CalculatorState.RESULT);
diff --git a/src/com/android/calculator2/CalculatorResult.java b/src/com/android/calculator2/CalculatorResult.java
index d14135c..a916c30 100644
--- a/src/com/android/calculator2/CalculatorResult.java
+++ b/src/com/android/calculator2/CalculatorResult.java
@@ -48,7 +48,7 @@ import android.support.v4.view.ViewCompat;
// A text widget that is "infinitely" scrollable to the right,
// and obtains the text to display via a callback to Logic.
public class CalculatorResult extends TextView {
- static final int MAX_RIGHT_SCROLL = 100000000;
+ static final int MAX_RIGHT_SCROLL = 10000000;
static final int INVALID = MAX_RIGHT_SCROLL + 10000;
// A larger value is unlikely to avoid running out of space
final OverScroller mScroller;
@@ -71,8 +71,10 @@ public class CalculatorResult extends TextView {
// Large positive values mean the decimal point is scrolled off the
// left of the display. Zero means decimal point is barely displayed
// on the right.
- private int mLastPos; // Position already reflected in display.
- private int mMinPos; // Maximum position before all digits disappear of the right.
+ private int mLastPos; // Position already reflected in display. Pixels.
+ private int mMinPos; // Minimum position before all digits disappear off the right. Pixels.
+ private int mMaxPos; // Maximum position before we start displaying the infinite
+ // sequence of trailing zeroes on the right. Pixels.
private Object mWidthLock = new Object();
// Protects the next two fields.
private int mWidthConstraint = -1;
@@ -109,14 +111,14 @@ public class CalculatorResult extends TextView {
// Ignore scrolls of error string, etc.
if (!mScrollable) return true;
mScroller.fling(mCurrentPos, 0, - (int) velocityX, 0 /* horizontal only */,
- mMinPos, MAX_RIGHT_SCROLL, 0, 0);
+ mMinPos, mMaxPos, 0, 0);
ViewCompat.postInvalidateOnAnimation(CalculatorResult.this);
return true;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
- // TODO: Should we be dealing with any edge effects here?
+ int distance = (int)distanceX;
if (!mScroller.isFinished()) {
mCurrentPos = mScroller.getFinalX();
}
@@ -124,9 +126,14 @@ public class CalculatorResult extends TextView {
stopActionMode();
CalculatorResult.this.cancelLongPress();
if (!mScrollable) return true;
+ if (mCurrentPos + distance < mMinPos) {
+ distance = mMinPos - mCurrentPos;
+ } else if (mCurrentPos + distance > mMaxPos) {
+ distance = mMaxPos - mCurrentPos;
+ }
int duration = (int)(e2.getEventTime() - e1.getEventTime());
if (duration < 1 || duration > 100) duration = 10;
- mScroller.startScroll(mCurrentPos, 0, (int)distanceX, 0, (int)duration);
+ mScroller.startScroll(mCurrentPos, 0, distance, 0, (int)duration);
ViewCompat.postInvalidateOnAnimation(CalculatorResult.this);
return true;
}
@@ -177,18 +184,45 @@ public class CalculatorResult extends TextView {
}
}
- // Display a new result, given initial displayed
- // precision and the string representing the whole part of
- // the number to be displayed.
- // We pass the string, instead of just the length, so we have
- // one less place to fix in case we ever decide to
- // correctly use a variable width font.
- void displayResult(int initPrec, String truncatedWholePart) {
+ // Given that the last non-zero digit is at pos, compute the precision we have to ask
+ // ask for to actually get the digit at pos displayed. This is not an identity
+ // function, since we may need to drop digits to the right to make room for the exponent.
+ private int addExpSpace(int lastDigit) {
+ if (lastDigit < getMaxChars() - 1) {
+ // The decimal point will be in view when displaying the rightmost digit.
+ // no exponent needed.
+ // TODO: This will change if we stop scrolling to the left of the decimal
+ // point, which might be desirable in the traditional scientific notation case.
+ return lastDigit;
+ }
+ // When the last digit is displayed, the exponent will look like "e-<lastDigit>".
+ // The length of that string is the extra precision we need.
+ return lastDigit + (int)Math.ceil(Math.log10((double)lastDigit)) + 2;
+ }
+
+ // Display a new result, given initial displayed precision, position of the rightmost
+ // nonzero digit (or Integer.MAX_VALUE if non-terminating), and the string representing
+ // the whole part of the number to be displayed.
+ // We pass the string, instead of just the length, so we have one less place to fix in case
+ // we ever decide to fully handle a variable width font.
+ void displayResult(int initPrec, int leastDigPos, String truncatedWholePart) {
mLastPos = INVALID;
synchronized(mWidthLock) {
mCurrentPos = initPrec * mCharWidth;
}
- mMinPos = - (int) Math.ceil(getPaint().measureText(truncatedWholePart));
+ // Should logically be
+ // mMinPos = - (int) Math.ceil(getPaint().measureText(truncatedWholePart)), but
+ // we eventually transalate to a character position by dividing by mCharWidth.
+ // To avoid rounding issues, we use the analogous computation here.
+ mMinPos = - truncatedWholePart.length() * mCharWidth;
+ if (leastDigPos < MAX_RIGHT_SCROLL) {
+ mMaxPos = Math.min(addExpSpace(leastDigPos) * mCharWidth, MAX_RIGHT_SCROLL);
+ } else {
+ mMaxPos = MAX_RIGHT_SCROLL;
+ }
+ mScrollable = (leastDigPos != (initPrec == -1 ? 0 : initPrec));
+ // We assume that initPrec allows most significant digit to be displayed.
+ // If there is nothing to the right of initPrec, there is no point in scrolling.
redisplay();
}
@@ -212,8 +246,6 @@ public class CalculatorResult extends TextView {
// would have been in had we not done so.
// This minimizes jumps as a result of scrolling. Result is NOT internationalized,
// uses "e" for exponent.
- // last_included[0] is set to the position of the last digit we actually include;
- // thus caller can tell whether result is exact.
public String formatResult(String res, int digs,
int maxDigs, boolean truncated,
boolean negative) {
@@ -313,13 +345,16 @@ public class CalculatorResult extends TextView {
return (currentCharPos >= BoundedRational.digitsRequired(rat));
}
- // May be called asynchronously from non-UI thread.
+ /**
+ * Return the maximum number of characters that will fit in the result display.
+ * May be called asynchronously from non-UI thread.
+ */
int getMaxChars() {
- // We only use 2/3 of the available space, since the left 1/3 of the result is not
- // visible when it is shown in large size.
+ // We only use 4/5 of the available space, since at least the left 4/5 of the result
+ // is not visible when it is shown in large size.
int result;
synchronized(mWidthLock) {
- result = 2 * mWidthConstraint / (3 * mCharWidth);
+ result = 4 * mWidthConstraint / (5 * mCharWidth);
// We can apparently finish evaluating before onMeasure in CalculatorText has been
// called, in which case we get 0 or -1 as the width constraint.
}
@@ -331,6 +366,19 @@ public class CalculatorResult extends TextView {
}
}
+ /**
+ * Return the fraction of the available character space occupied by the
+ * current result.
+ * Should be called only with a valid result displayed.
+ */
+ float getOccupancy() {
+ if (mScrollable) {
+ return 1.0f;
+ } else {
+ return (float)getText().length() / getMaxChars();
+ }
+ }
+
int getCurrentCharPos() {
synchronized(mWidthLock) {
return mCurrentPos/mCharWidth;
@@ -359,7 +407,6 @@ public class CalculatorResult extends TextView {
setText(result);
}
mValid = true;
- mScrollable = true;
}
@Override
diff --git a/src/com/android/calculator2/Evaluator.java b/src/com/android/calculator2/Evaluator.java
index 6f508c4..8764a99 100644
--- a/src/com/android/calculator2/Evaluator.java
+++ b/src/com/android/calculator2/Evaluator.java
@@ -425,8 +425,8 @@ class Evaluator {
// checking for change.
int init_prec = result.mInitDisplayPrec;
int msd = getMsdPos(mCache);
- int new_init_prec = getPreferredPrec(mCache, msd,
- BoundedRational.digitsRequired(mRatVal));
+ int leastDigPos = BoundedRational.digitsRequired(mRatVal);
+ int new_init_prec = getPreferredPrec(mCache, msd, leastDigPos);
if (new_init_prec < init_prec) {
init_prec = new_init_prec;
} else {
@@ -434,7 +434,7 @@ class Evaluator {
// happen if they're not. e.g. because
// CalculatorResult.MAX_WIDTH was too small.
}
- mCalculator.onEvaluate(init_prec,truncatedWholePart);
+ mCalculator.onEvaluate(init_prec, leastDigPos, truncatedWholePart);
}
@Override
protected void onCancelled(InitialResult result) {
@@ -712,7 +712,8 @@ class Evaluator {
// Notify immediately, reusing existing result.
int dotPos = mCache.indexOf('.');
String truncatedWholePart = mCache.substring(0, dotPos);
- mCalculator.onEvaluate(mLastDigs,truncatedWholePart);
+ int leastDigPos = BoundedRational.digitsRequired(mRatVal);
+ mCalculator.onEvaluate(mLastDigs, leastDigPos, truncatedWholePart);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-23 10:01:48 +0000